[Federal Register Volume 75, Number 188 (Wednesday, September 29, 2010)]
[Proposed Rules]
[Pages 60036-60064]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-24347]
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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
[Docket No. NHTSA-2010-0132]
RIN 2127-AK17
Federal Motor Vehicle Safety Standards; New Pneumatic Tires for
Motor Vehicles With a GVWR of More Than 4,536 Kilograms (10,000 Pounds)
and Motorcycles
AGENCY: National Highway Traffic Safety Administration (NHTSA),
Department of Transportation (DOT).
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This NPRM proposes to upgrade Federal Motor Vehicle Safety
Standard (FMVSS) No. 119, which specifies requirements for new truck
tires. We propose to amend FMVSS No. 119 to adopt more stringent
endurance test requirements and a new high speed test for several heavy
load range tires for vehicles with gross vehicle weight rating (GVWR)
of more than 4,536 kilograms (10,000 pounds). We are also proposing
that FMVSS No. 119 require that the tire sidewall be labeled with the
tire's maximum speed rating.
[[Page 60037]]
DATES: You should submit your comments early enough to ensure that the
Docket receives them not later than November 29, 2010.
ADDRESSES: You may submit comments (identified by the NHTSA Docket ID
Number above) by any of the following methods:
Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the online instructions for submitting
comments.
Mail: Docket Management Facility: U.S. Department of
Transportation, 1200 New Jersey Avenue, SE., West Building Ground
Floor, Room W12-140, Washington, DC 20590-0001.
Hand Delivery or Courier: West Building Ground Floor, Room
W12-140, 1200 New Jersey Avenue, SE., between 9 a.m. and 5 p.m. ET,
Monday through Friday, except Federal holidays.
Fax: 202-493-2251.
Instructions: For detailed instructions on submitting comments and
additional information on the rulemaking process, see the Public
Participation heading of the Supplementary Information section of this
document. Note that all comments received will be posted without change
to http://www.regulations.gov, including any personal information
provided. Please see the Privacy Act heading below.
Privacy Act: Anyone is able to search the electronic form of all
comments received into any of our dockets by the name of the individual
submitting the comment (or signing the comment, if submitted on behalf
of an association, business, labor union, etc.). You may review DOT's
complete Privacy Act Statement in the Federal Register published on
April 11, 2000 (65 FR 19477-78).
Docket: For access to the docket to read background documents or
comments received, go to http://www.regulations.gov or the street
address listed above. Follow the online instructions for accessing the
dockets.
FOR FURTHER INFORMATION CONTACT: For technical issues, you may call
George Soodoo, NHTSA Office of Rulemaking (Telephone: 202-366-2720)
(Fax: 202-493-2739). For legal issues, you may call Steve Wood, NHTSA
Office of Chief Counsel (Telephone: 202-366-2992) (Fax: 202-366-3820).
The mailing address for these officials is: National Highway Traffic
Safety Administration, U.S. Department of Transportation, 1200 New
Jersey Avenue, SE., West Building, Washington, DC 20590.
SUPPLEMENTARY INFORMATION
Table of Contents
I. Background
II. Overview of Endurance Test and High Speed Test Proposals
a. Endurance Test
b. High Speed Test
III. NHTSA Tire Testing
a. Test Program
b. Summary
IV. Proposed Endurance Test
a. Test Speed
b. Load
c. Inflation Pressure
d. Duration
e. Ambient Temperature
f. Endurance Test Conclusions
V. Proposed High Speed Test
a. Test Speed and Break-In Procedure
b. Load
c. Inflation Pressure
d. Duration
e. Ambient Temperature
VI. Tire Maximum Speed Marking
VII. Other Issues
a. Alternatives Considered
1. International Standards
2. ASTM Truck/Bus Tire Test Development Task Group
3. Rubber Manufacturers Association
b. Deep Tread Truck Tires
c. Correction of Table III
d. Separate Standard
VIII. Proposed Effective Date
IX. Costs and Benefits
X. Rulemaking Analyses and Notices
XI. Public Participation
I. Background
This NPRM proposes to upgrade Federal Motor Vehicle Safety Standard
(FMVSS) No. 119 (49 CFR 571.119) which, prior to the passage of the
Transportation Recall Enhancement, Accountability and Documentation
(TREAD) Act of 2000, had a wide application to new pneumatic tires for
vehicles other than passenger cars. In response to the TREAD Act,\1\ a
June 26, 2003 final rule upgraded the standard's requirements \2\ for
tires designed for multipurpose passenger vehicles, trucks and buses
with a GVWR of 4,536 kilograms (kg) (10,000 pounds (lb)) or less, and
moved those enhanced requirements to a new Federal Motor Vehicle Safety
Standard No. 139 for new pneumatic radial tires for light vehicles.
Requirements for load range C, D, and E tires used on light trucks and
vans formerly set forth in FMVSS No. 119 were thus moved from that
standard to FMVSS No. 139.\3\ The June 26, 2003 final rule changed the
title, scope, purpose and application sections of FMVSS No. 119 to
reflect that the standard thereafter applied to only tires for
motorcycles and vehicles with a GVWR greater than 4,536 kg (10,000 lb),
but made no changes to FMVSS No. 119's performance requirements for
those tires.\4\
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\1\ Section 10 of the TREAD Act stated that the Secretary of
Transportation shall conduct a rulemaking to revise and update the
tire standards published at 49 CFR 571.109 and 49 CFR 571.119. The
Act provided that the Secretary shall complete the rulemaking under
this section not later than June 1, 2002. November 1, 2000, Public
Law 106-414, 114 Stat. 1800.
\2\ 68 FR 38116; June 26, 2003, Docket NHTSA-03-15400; response
to petitions for reconsideration, 71 FR 877, January 6, 2006, Docket
2005-23439; technical amendments, 72 FR 49207, August 28, 2007,
Docket 2007-29083. See also final rule, correcting amendments, 73 FR
72357; November 28, 2008, Docket 2007-29083.
\3\ The term ``load range'' with a letter (C, D, E, etc.) is
used to identify the load and inflation limits of tires used on
light or heavy trucks, which increase in alphabetical sequence. For
example, a load range E tire is able to handle greater loads and
higher inflation pressures than a load range D tire.
\4\ FMVSS No. 119 has been in effect since the original rule was
published in 1973. The original standard applied to tires used on
vehicles other than passenger cars, which included pickup trucks,
multipurpose passenger vehicles, vans, and heavy vehicles. As a
result of the TREAD Act mandate to upgrade FMVSS No. 109 and FMVSS
No. 119, the agency revised the applicability of the tire standards
to reflect the weight of the vehicle on which the tire is used.
Given the increased consumer use to light trucks and vans (LTVs) for
passenger transportation purposes over the past 20 years, the agency
believed it was important to revise the applicability of the
standards. As a result, the new tire standard for light vehicle
tires, FMVSS No. 139, which was published in 2003, applies to tires
used on vehicles with a gross vehicle weight rating of 4,536 kg
(10,000 pounds) or less, and FMVSS No. 119 now applies to tires for
vehicles with a gross vehicle weight rating of over 4,536 kg (10,000
pounds). (It is noted that other tires required to comply with No.
119 are new pneumatic light truck tires with tread depth of 18/32
inch or greater, light truck bias-ply tires, bias-ply tires used on
vehicles with a GVWR of more than 4,536 kg (10,000 lb), and tires
for use on special-use trailer (ST, farm implement and 8-12 rim or
lower diameter code). The tires affected by this rulemaking are
those used on heavy vehicles with a GVWR of more than 4,536 kg
(10,000 lb) that are not for speed-restricted service.)
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NHTSA stated in the NPRM developing FMVSS No. 139 that the TREAD
Act deadline to complete the tire upgrade by June 2002 did not allow
the agency time to study and analyze sufficiently the different issues
presented by medium and heavy vehicle tires, and that NHTSA will
examine these types of tires after completion of the FMVSS No. 139
rulemaking (67 FR 10050, 10061; March 5, 2002). In today's document, we
are proceeding to propose to make more stringent FMVSS No. 119's
endurance test, adopt a new high speed test for several load range
tires used on heavy vehicles, and require that the tire sidewall be
labeled with the tire's maximum speed rating.
The agency is initiating this rulemaking to upgrade radial truck
tires that have a load range of F, G, H, J, and L, and that are not for
speed-restricted service (``non-speed-restricted service tires'').
Tires used for speed-restricted service, known as ``speed-restricted
service tires,'' are those with a maximum speed rating of 90 km/h (55
mph) or less. Non-speed-restricted service tires
[[Page 60038]]
are those with a maximum speed rating above 90 km/h (55 mph). ``Maximum
speed rating'' is the maximum speed, as specified by the manufacturer,
at which the tire can carry a load corresponding to its maximum load
rating for single usage at the corresponding inflation pressure.\5\ We
have commenced this rulemaking primarily because we have tentatively
determined that the FMVSS No. 119 performance tests developed in 1973
should be updated to reflect the increased operational speeds and
duration of truck tires in commercial service. NHTSA has tentatively
determined that this NPRM would have a beneficial effect on safety in
that it would increase tire durability as tires are held to more
stringent standards than currently required.
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\5\ This NPRM would define these terms in FMVSS No. 119 to
differentiate the types of service for which tires are used and the
requirements in the standard that would apply to the different types
of tire.
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FMVSS No. 119
FMVSS No. 119 specifies performance and marking requirements for
tires for use on motorcycles and on motor vehicles with a GVWR of more
than 4,536 kg (10,000 lb). Heavy vehicle tires regulated by FMVSS No.
119 are used in a wide variety of vehicle applications, such as
delivery trucks, line haul trucks, transit buses, and logging trucks.
FMVSS No. 119 includes a static test for tire strength, and dynamic
tests for tire endurance and high-speed performance. The endurance test
evaluates resistance to heat buildup when the tire is run at stepped-up
loads at or near its rated load nonstop for a total of 47 hours. A
high-speed test evaluates resistance to heat buildup when the tire is
run at a certain percentage of its maximum load at stepped-up speeds
for a specified interval at each speed.\6\ FMVSS No. 119's high-speed
performance requirement applies only to motorcycle tires and those with
a rim diameter code of 14.5 or less (tires made to fit rims of diameter
of 14.5 inches or less). Since this size restriction excludes all heavy
vehicle tires currently listed in the Tire and Rim Association 2009
Year Book, the endurance test is currently the only dynamic test to
which heavy vehicle tires must comply.
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\6\ See, e.g., S6.2 of FMVSS No. 139.
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Today's NPRM would upgrade FMVSS No. 119 by proposing to adopt a
more stringent endurance test, add a new high speed test, and include
maximum speed rating labeling requirements for new radial tires used on
heavy truck and bus applications, i.e., load range F, G, H, J, and L
tires that are not for speed-restricted service, which the agency
believes comprise about 98 percent of the truck tires sold in the
United States. These load range tires are typically used on heavy
trucks for regional haul and long haul operations as well as on
motorcoaches, and these load range tires have speed ratings ranging
from 55-81 mph. Higher load range tires (i.e., load ranges M and N) are
more often used in heavy mixed-use service (on/off-road operations in
lower speed applications), such as construction, logging, crane, and
rigging operations. However, the agency is also considering requiring
non-speed-restricted, load range M radial tires to comply with the
upgraded endurance and new high speed test because some of these tires
are used in similar applications in which the load range L tires are
used. The agency is not proposing to upgrade non-speed-restricted
service load range N radial tires since they represent less than 1
percent of the heavy vehicle tire market and are typically used in
lower speed operations.
II. Overview of Endurance Test and High Speed Test Proposals
The proposed upgrade to the endurance test and the proposed
adoption of a high speed test are based on the results of NHTSA's heavy
truck tire tests, discussed later in the ``NHTSA Tire Testing'' section
of this preamble.
a. Endurance Test
The purpose of the endurance test is to evaluate heavy truck tire
performance at highway speeds for a long duration. The endurance test
in FMVSS No. 119 applies to truck tires with load ranges F through N
that are not for speed-restricted service. The test parameters used for
the endurance test in FMVSS No. 119 include test speed, load, inflation
pressure, duration, and ambient temperature. This NPRM proposes to
upgrade the endurance test by changing some of these parameters to
achieve more stringent conditions when testing load range F, G, H, J,
and L radial tires that are not for speed-restricted service. Current
endurance test parameters for load range N radial tires, load range F,
G, H, J, L, M, and N tires that are for speed-restricted service, bias-
ply tires, light truck tires (tread depth 18/32 inch or more), and
motorcycle tires, would remain unchanged in the standard.
Test Speed
The current test speed for the endurance test in FMVSS No. 119
depends on the load range of the tire. Load range F tires are tested at
64 km/h (40 mph) on the 67-inch diameter test road wheel; load range G
tires are tested at 56 km/h (35 mph); and tires with a load range H, J,
L, M, or N are tested at 48 km/h (30 mph). NHTSA proposes to raise the
test speed for the endurance test to 80 km/h (50 mph) for load range F,
G, H, J, and L tires. This represents a 25 percent increase in speed
for a load range F tire, a 43 percent increase for a load range G tire,
and a 67 percent increase for load range H, J, and L tires that are not
for speed-restricted service.
Load
The current test loads for the endurance test in FMVSS No. 119,
identical for all the load ranges F through N, are specified as a
percentage of the maximum load rating of the tire, and are 66 percent,
84 percent, and 101 percent. The loads are applied in a stepped fashion
for durations of 7 hours, 16 hours, and 24 hours, respectively. NHTSA
proposes to change the load combination for the endurance test to 85/
90/100 percent of the tire's maximum load rating labeled on the tire's
sidewall, from the 66/84/101 percent combination currently required.
Inflation Pressure
The current test inflation pressure specified in FMVSS No. 119 is
the inflation pressure corresponding to the maximum load rating labeled
on the tire's sidewall. NHTSA proposes to set the test inflation
pressure at 80 percent of the sidewall-labeled inflation pressure that
corresponds to the tire's maximum load rating. This represents a 20
percent decrease from the current endurance test, which requires tires
to be fully inflated.
Duration
The current duration for the endurance test in FMVSS No. 119 is 47
hours: 7 hours at 66 percent load, 16 hours at 84 percent load, and 24
hours at 101 percent load. NHTSA proposes to leave FMVSS No. 119's
endurance test duration at 47 hours.
Ambient Temperature
The ambient temperature specified for the endurance test in FMVSS
No. 119 is 35 [deg]C (95 [deg]F). NHTSA proposes to add an ambient
temperature tolerance, and thus proposes an ambient of 35 [deg]C 3 [deg]C (95 [deg]F 5 [deg]F) for the endurance
test.
b. High Speed Test
The high speed test evaluates tire performance at higher speeds for
shorter durations. FMVSS No. 119's high speed test currently applies
only to motorcycle tires and to tires with rim diameters of 14.5 inches
or below, and does not
[[Page 60039]]
apply to truck tires. The test parameters used for the high speed test
in FMVSS No. 119 and in other tire standards include speed, load,
inflation pressure, duration, and ambient temperature. This NPRM
proposes to adopt a high speed test for load range F, G, H, J, and L
tires that are not for speed-restricted service, as these are typically
installed on vehicles in regional or long-haul service. The high-speed
test would be initiated after a 2-hour break-in at 80 km/h (50 mph) and
85 percent of maximum load rating, with inflation pressure at 90
percent of maximum.
Test Speed
NHTSA proposes to set the test speed for the high-speed test at the
tire's maximum speed less 20 km/h (12 mph) for step 1, maximum speed
less 10 km/h (6 mph) for step 2, and at maximum speed for the final
step. This would be a new approach for testing tires under the Federal
motor vehicle safety standards, as motorcycle and passenger car tires
are tested to one unvarying set of test speeds. The approach proposed
in this NPRM is similar to that used by the United Nations Economic
Commission for Europe (ECE) tire Regulations which establish tire test
speeds based on the maximum rated speed of the tire, and is along the
lines of a suggestion from the Rubber Manufacturers Association
(RMA).\7\
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\7\ See Docket No. NHTSA 2002-13707-0016.1, RMA Perspective on
the FMVSS 119 Revisions and Updates Mandated by the TREAD Act.
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Load
NHTSA proposes to set the test load for the high-speed test at 85
percent of the maximum load rating for the tire. The maximum load
rating would be based on the tire sidewall marking per single tire use
application.
Inflation Pressure
NHTSA proposes that the high-speed test inflation pressure be set
at 90 percent of the sidewall-labeled inflation pressure that
corresponds to the tire's maximum load rating.
Duration
NHTSA proposes a 90-minute duration for FMVSS No. 119's high-speed
test, consisting of three 30-minute speed steps at the proposed test
speeds.
Ambient Temperature
NHTSA proposes an ambient temperature range of 35 [deg]C 3 [deg]C (95 [deg]F 5 [deg]F) for the FMVSS No. 119
high speed test upgrade.
III. NHTSA Tire Testing
a. Test Program
After passage of the TREAD Act, NHTSA began testing new heavy truck
tires to assess the performance of current tires in endurance and high
speed tests, and how load, inflation pressure, speed and duration
affect tire performance. We tested more than 430 new heavy truck tires
with load ranges G through N that were designed for commercial vehicle
applications. The tires selected included a mixture of tire brands,
models and sizes.
Testing was performed in two phases. In Phase I, new load range G
tires were tested for durability (``endurance'') and robustness at
speed (``high speed''). Since the purpose of Phase I testing was to
assess the current level of performance for truck tires, the test
matrix for this phase included both destructive (extended duration) and
non-destructive tests. The purpose of Phase II testing was to generate
data with which specific proposals could be developed for an NPRM to
upgrade FMVSS No. 119. In Phase II, the test conditions were further
refined from Phase I, and the group of tires tested was expanded to
include load ranges H, J, L and N. Additional testing was also
conducted for tires with load ranges F, J, and L, and speed ratings
less than 75 mph.
All of the tires tested were commercially available at the time of
testing. For both Phases I and II, NHTSA developed test matrices that
included the performance parameters of speed, load, inflation pressure,
and test duration. The test matrices were developed with a series of
test conditions that increased in severity for tire performance. The
ambient temperature used in the testing for both Phase I and Phase II
was 35 [deg]C 3 [deg]C (95 [deg]F 5 [deg]F).
All tires were conditioned at the ambient temperature of 35 [deg]C
3 [deg]C (95 [deg]F 5 [deg]F) for 3 hours
prior to testing. Testing was conducted on a 67-inch diameter curved
test road wheel.\8\
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\8\ Throughout this preamble, we use test speeds in miles per
hour (mph) when presenting the test matrices, the test conditions,
and the test results for the baseline tests, as specified in the
current FMVSS No. 119. However, for the other tests in both the
endurance and high speed test matrices, we selected test speeds in
kilometers per hour (km/h) to be consistent with the metrification
of the Federal motor vehicle safety standards. Some of the Tables
presented in the preamble show speeds in miles per hour only, to
facilitate comparison with the baseline test speeds.
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Phase I Testing
In Phase I, NHTSA conducted testing on 180 new, size 11R22.5, load
range G, heavy truck tires with a rib-type tread.\9\ The 11R22.5 tire
size was chosen due to its use in on-road applications for heavy
vehicles: tire size 11R22.5 represents approximately 24 percent and 22
percent of the original equipment and replacement tire markets,
respectively. We tested tires from brands Hankook, Dayton, Bridgestone,
and General, all with tire size 11R22.5, load range G, and rib-type
treads. Based on suggestions \10\ from the Rubber Manufacturers
Association (RMA), the Tire Industry Association (TIA), and the Tread
Rubber/Tire Repair Materials Manufacturers Group (TRMG), we tested only
rib-type tires, typically used on steer axle and trailer axle
positions, to focus on a single tread type. Tires were tested to
determine levels of endurance and high-speed performance under a
variety of test conditions.
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\9\ In the tire size description, the ``11'' represents the tire
section width in inches, the ``R'' identifies the tire as a radial
tire, and the ``22.5'' represents the tire rim diameter code, which
equates to a rim diameter of 22.5 inches.
\10\ See Docket No. NHTSA-2002-13707.
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Phase I Endurance Test:
For the endurance test, we selected 120 new load range G tires from
Hankook, Dayton, Bridgestone and General. The Phase I endurance test
matrix consisted of 10 groups of varied test conditions, or ``Test
Methods,'' \11\ as shown below in Table 1, ``Phase I Endurance Test
Matrix.'' Other than in Test Methods 1 and 1A, three samples of each
tire brand were tested for each Test Method (TM) in the matrix. Test
Method 1 used one sample of each tire brand, and Test Method 1A used
two samples of each tire brand.
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\11\ Test Method 1A is considered a part of Test Method 1.
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Each TM consisted of a combination of the selected tire load,
inflation pressure, test speed, and a specified duration at each load
condition. Testing was performed so that each TM varied in severity by
changing the load, inflation pressure or speed.
The applied test loads ranged from 66 percent of the maximum load
rating to 110 percent of the maximum load rating. The loads used are
similar to those used in the light vehicle tire research program that
was conducted in 2001-2002 to support the upgrade of the endurance test
for FMVSS No. 139. The stepped-up load combinations included 85, 90,
and 100 percent; 90, 100, and 110 percent; and 100, 110, and 115
percent, which allowed the agency to understand limits of performance
for light vehicle tires, including light truck tires with load ranges
C, D, and E. For this research on medium and heavy duty truck tires,
the agency also wanted
[[Page 60040]]
to understand the upper limits of performance for these tires when they
are tested at normal loading conditions and at loads beyond their
maximum load rating. As a result, we included stepped-up loads to 90/
100/110 percent of the maximum load rating of the tires, since this
represents an overloading condition for a truck tire on the test road-
wheel.
Inflation pressures ranged from 80 to 100 percent of the maximum
inflation pressure stated on the sidewall of the tires. The current
endurance test in FMVSS No. 119 requires that the tire be tested at 100
percent of its maximum inflation pressure, but the agency sought to
evaluate truck tires' performance when tested at some level of under-
inflation, because that condition is occurring in real-world
operation.\12\ We chose 80 percent of the maximum inflation pressure as
the lowest value for this testing, primarily because the truck industry
considers a tire at that level of under-inflation to be significantly
under-inflated.
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\12\ See Federal Motor Carrier Safety Administration, Final
Report, ``Commercial Vehicle Tire Condition Sensors,'' November
2003, at 7.
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The test speeds ranged from 56 km/h (35 mph) to 120 km/h (75 mph),
which we believe represented the typical operating range of speeds for
trucks using tires with the specified load ranges. Each tire was
conditioned at the ambient test temperature of 35 [deg]C 3
[deg]C (95 [deg]F 5 [deg]F) for three hours. No break-in
procedure was performed on tires tested for endurance performance since
none is performed in the existing FMVSS No. 119 endurance test
procedure. Table 1, ``Phase I Endurance Test Matrix,'' below shows the
test parameters used for the endurance test in Phase I and the
structure of the test duration for the three samples in each Test
Method. We note that for TMs 2-9, tire sample number 3 was tested for
an additional amount of time after the rest of the TM was completed,
which is why Table 1 shows an extra line for sample number 3 for these
TMs.
[[Page 60041]]
[GRAPHIC] [TIFF OMITTED] TP29SE10.005
[[Page 60042]]
[GRAPHIC] [TIFF OMITTED] TP29SE10.006
The test parameters for the baseline tests (Test Method 1, load
step 1-3) represent the current FMVSS No. 119 level for the endurance
test. The tires (one sample of each tire brand) were tested at 56 km/h
(35 mph), with a load of 66 percent of maximum load rating for 7 hours,
84 percent of maximum load rating for 16 hours, 101 percent of maximum
load for 24 hours, and with an inflation pressure of 100 percent of the
maximum inflation pressure value labeled on the sidewall. After the end
of the 47-hour test, the tires were tested for an additional 48 hours,
at a load of 110 percent of maximum load rating, and with the test
parameters of speed, inflation pressure, and ambient temperature
unchanged. Therefore, the total duration for the baseline endurance
tests in Test Method 1 was 95 hours (47 hours per FMVSS No. 119 plus an
additional 48 hours).
There were no failures in the baseline tests completed on the first
of three samples for each tire brand. We then conducted a second
baseline test by increasing the test speed for the remaining two
samples to 80 km/h (50 mph) for the entire test, as shown in Test
Method 1A. The inflation pressure and load parameters for the second
baseline test were the same as in Test Method 1. The test load for the
remaining two samples was 110 percent of maximum load rating for the
last 48 hours of the test. The objective of the baseline tests in Test
Method 1A was to determine how well tires performed under conditions
slightly more stringent than the current endurance test in FMVSS No.
119.
As shown in Test Methods 2 through 9 (Table 1, above), test
severity was increased by increasing the test speed, increasing the
test loads, and reducing the inflation pressure. Road-wheel tests (not
to failure) were conducted for 47 hours on two samples. The third
sample was tested to 95 hours or until failure, whichever occurred
first, with the load for the last 48 hours of the test being the same
load applied in the last step for the 47-hour portion of the test.
All tires were inspected for belt separation, tread separation, and
any other visual evidence of damage. For Test Method 10, all three tire
samples were tested to 95 hours or until failure, whichever occurred
first.
Phase I Endurance Test Results:
Of the 120 new tires tested for endurance performance under a
variety of test conditions, 24 experienced failures. Of the 24
failures, 15 failed as a result of tread separation, 2 failed as a
result of belt separation; 2 failed as a result of shoulder split; and
2 failed as a result of chunking. The remaining 3 failures consisted of
other failure types such as tread splitting and sidewall separation.
Table 2, ``Phase I Endurance Test Results,'' summarizes the results for
the endurance test on the four tire brands tested. Data for individual
tests have been placed in the docket (NHTSA-2002-13707).
The Test Methods included in Table 2 are the same test methods for
which the test conditions are shown in detail in Table 1. The test
results in Table 2 show that the first sample for each of the four tire
brands completed 95 hours for the baseline test in Test Method 1. The
remaining two tire samples for each brand were tested to Test Method
1A, using the same test parameters, except for the test speed, which
was increased from 56 km/h (35 mph) to 80 km/h (50 mph). Also note that
for Test Methods 2 through 10, the first two samples of each Test
Method were tested to 47 hours, while the third sample was tested to 95
hours. Four test errors occurred, where the test road-wheel stopped due
to equipment or mechanical failure. These test errors are noted in
Table 2 with an asterisk.
[[Page 60043]]
Table 2--Phase I Endurance Test Results
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Tire brands (hours completed)
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Target (hours)
Hankook
Dayton
Bridgestone
General
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Test Method No. Sample No.
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1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
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1............................... 95 ...... ...... 95 ...... ...... 95 ...... ...... 95 ...... ...... 95 ...... ......
1A.............................. ...... 95 95 ...... 95 95 ...... 95 95 ...... 95 95 ...... 95 95
2............................... 47 47 95 47 47 95 47 47 95 47 47 95 47 47 95
3............................... 47 47 95 1 47 95 47 47 95 47 47 95 47 47 95
4............................... 47 47 95 47 47 95 47 47 37 47 47 37 47 47 95
5............................... 47 47 95 47 47 95 43 44 53 47 44* 95 47 47 95
6............................... 47 47 95 47 47 95 47 47 95 47 47 95 47 47 95
7............................... 47 47 95 47 47 95 47 47 69 47 47 95 47 47 95
8............................... 47 47 95 47 44* 95 47 47 95 47 47 92 47 47 32
9............................... 47 47 95 47 47 95 28 28 23 47 47 95 42 47 41
10.............................. 47 47 95 12 50 46* 27 3 14 31* 27 30 25 36 24
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Note: * Test error.
Overall, the tires tested performed well throughout the endurance
test matrix, particularly Test Methods 1 through 8, for which each tire
brand had at least one sample that completed 47 hours of those Test
Methods. The results indicate that decreased inflation pressure and
increased speed of Test Method 9, and the even higher speed of Test
Method 10, define the upper boundary of current new tire performance.
For Test Methods 8 and 9, the inflation pressure was decreased to 80
percent of maximum inflation pressure, and the test speed was increased
from 88 km/h (55 mph) to 100 km/h (63 mph). In addition, the test loads
were increased in Test Method 9 to 90/100/110 percent of the tire's
maximum load rating. For Test Method 10, inflation was increased to 100
percent and test speed raised to 120 km/h (75 mph), the same test speed
used in the endurance test for light vehicle tires in FMVSS No. 139.
The results indicate that higher speeds and lower inflation pressure
appear to have the most impact on tire failure compared with changes in
test load or duration.
Phase I High Speed Test:
We tested 60 new load range G tires from major tire manufacturers
Hankook, Dayton, Bridgestone, and General for high speed performance.
Since the FMVSS No. 119 high speed requirements currently apply only to
tires with a rim diameter code of 14.5 or less and to motorcycle tires,
the performance levels for the high speed baseline tests in our heavy
truck tire test program (see Test Method A of Table 3 below, ``Phase I
High Speed Test Matrix'') were set at the FMVSS No. 119 levels of
performance for those tires, simply as a starting point for the test
program. Test conditions were varied to produce different levels of
severity by changing the load, inflation pressure and speed. See Table
3, ``Phase I High Speed Test Matrix,'' below for a summary of the high
speed test matrix.
[[Page 60044]]
[GRAPHIC] [TIFF OMITTED] TP29SE10.007
Test severity, as defined by more severe running conditions (i.e.
increased load, higher speed, or reduced inflation pressure), increased
from Test Method A to Test Method E. In Test Method A, the first three
speed steps represent the current conditions in FMVSS No. 119
(specified for applicable tires) and the next three test speeds
represent speed conditions beyond those currently in FMVSS No. 119. The
tires were tested to a stepped-up speed profile starting at 120 km/h
(75 mph), with a load condition of 88 percent of maximum load rating
for 30 minutes. The test speed was increased in 5-mph increments every
30 minutes until failure or a speed of 160 km/h (100 mph) was achieved,
whichever occurred first. Therefore, the target completion time for the
baseline high speed test was 3 hours for a total of six speed steps for
Test Method A only. The primary reason for testing beyond 137 km/h (85
mph) in the baseline tests was to assess the upper boundary of high
speed performance for heavy truck tires.
The initial test speed for Test Methods B through E was set to 120
km/h (75 mph), and increased to 130 km/h (81 mph) and 140 km/h (88 mph)
in 30-minute intervals for a total of three test steps. The 10-km/h
increments were used to increase the speed severity moderately for tire
samples as they advanced through the different test methods. For each
tire brand tested, the first two samples were tested for three 30-
minute speed steps, for a total test duration of 1.5 hours. The third
sample was tested for an additional hour at the last speed step of 140
km/h (88 mph), resulting in a test duration of 2.5 hours.
The test load was based on the maximum load rating for the subject
tire as labeled on the sidewall. The test load ranged from 80 percent
of maximum load rating to 90 percent of maximum load rating. Inflation
pressures ranged from 90 percent to 100 percent of maximum pressure
labeled on the sidewall.
Each tire was conditioned for the test at an ambient temperature of
35 [deg]C 3 [deg]C (95 [deg]F 5 [deg]F) for
three hours, and then broken in for two hours under 88 percent of
maximum load and 100
[[Page 60045]]
percent maximum inflation pressure at 80 km/h (50 mph).\13\ The tire
was allowed to cool to 35 [deg]C 3 [deg]C (95 [deg]F
5 [deg]F) and the inflation pressure was adjusted to
applicable pressure immediately before the test. The break-in procedure
was performed to bring the tire to operating temperature, which allows
the tire to flex, expand and contract such that air within the tire may
fully permeate into the tire cavity. The break-in procedure also
removes mold release agents and flashings produced by the molding
process, which could contribute to variability in the test.
---------------------------------------------------------------------------
\13\ Traditionally, a high speed test has an initial break-in
step that involves a tire running on the roadwheel under specified
conditions to allow for tire growth. The endurance test does not
need a break-in step primarily because the 47-hour test duration
allows time for break-in during the test.
---------------------------------------------------------------------------
At the completion of the test, tires were visually inspected for
belt separation, tread separation, and evidence of damage.
Phase I High Speed Test Results:
Of the 60 new tires tested for high speed performance under a
variety of test conditions, 7 experienced test failures. Of these 7
failures, 4 failed as a result of tread chunking, 2 failed as a result
of tread separation, and 1 failed due to belt separation. Most of these
failures occurred in Test Method A at test speeds of 152 km/h (95 mph)
or at 160 km/h (100 mph). Table 4 below, ``Phase I High Speed Test
Results (Hours Completed),'' shows how the tires performed, as tested
under each test method. The Test Methods included in Table 4 are the
same Test Methods for which the test conditions are shown in detail in
Table 3.
Table 4--Phase I High Speed Test Results (Hours Completed)
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Tire Brands (hours completed)
-----------------------------------------------------------------------------------------------
Target hours
Hankook
Dayton
Bridgestone
General
-----------------------------------------------------------------------------------------------------------------------
Test Method Sample No.
-----------------------------------------------------------------------------------------------------------------------
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
--------------------------------------------------------------------------------------------------------------------------------------------------------
A............................... 3.0 3.0 3.0 3.0 3.0 3.0 2.3 2.8 2.5 2.9 3.0 2.9 3.0 3.0 2.8
B............................... 1.5 1.5 2.5 1.5 1.5 2.5 1.5 1.5 2.5 1.5 1.5 2.5 1.5 1.5 2.5
C............................... 1.5 1.5 2.5 1.5 1.5 2.5 1.5 1.5 2.5 1.5 1.5 2.5 1.5 1.5 2.5
D............................... 1.5 1.5 2.5 1.5 1.5 2.5 1.5 1.5 2.5 1.5 1.5 2.5 1.5 1.5 2.5
E............................... 1.5 1.5 2.5 1.5 1.5 2.5 1.5 1.5 1.8 1.5 1.5 2.5 1.5 1.5 2.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Test Method A was extended so that samples would be tested to the
baseline FMVSS No. 119 conditions and then tested at increased speeds.
For Test Method A, speed was increased beyond the FMVSS No. 119 test
speeds to 90, 95, and 100 mph, in 30-minute increments (the total test
duration target was three hours). Inflation pressure and load were
unchanged. Each sample was tested at 88 percent of maximum load rating,
100 percent inflation pressure and to speeds that were increased in 30-
minute increments to a stepped profile, initiating at 120 km/h (75 mph)
and concluding at 160 km/h (100 mph) or failure, whichever occurred
first.
Overall, the new tires tested to the high-speed matrix performed
well, as shown in Table 4. All of the 7 tires that failed completed at
least 1.5 hours, which represents the first three 30-minute speed steps
of the targeted test duration. Test Method A was designed to test tires
to 100 mph or failure, whichever occurred first. The results for Test
Method A reveal that all of the tires were able to withstand speeds of
up to 90 mph, when inflated at 100 percent of maximum inflation
pressure. The results also show that all of the tires tested to Test
Methods B through E were able to complete the 1.5 hours at test speeds
of 120, 130, and 140 km/h (75, 81 and 88 mph). In addition, when tested
to an additional hour at the last speed step of 140 km/h (88 mph), all
the tires tested, except one Dayton tire, were able to complete the
entire 2.5 hours of the high-speed test.
Phase II Testing
While Phase I testing provided NHTSA with a general understanding
of the current level of performance for new heavy duty truck tires,
Phase II testing refined the test matrices to develop possible,
practicable, proposals to upgrade the endurance and high speed tests in
FMVSS No. 119. In Phase II, NHTSA tested 365 new tires. Testing also
was expanded to include test tires of additional tire sizes (385/65 R
22.5 and 315/80 R 22.5), load ranges (F, H, J, L, and N tires, and load
range G ``bias ply'' type tires), brands from other manufacturers
(Continental, Goodyear, Michelin, Kumho, and Yokohama), and steer,
drive, and all-position tread types, as shown in Table 5.
These tires included speed ratings ranging from 56 mph to 75 mph.
Most of the tires were tested for both endurance performance and for
high-speed performance. Some tire models were tested in 2005, and
certain tire models tested were retested in 2008 to validate their
performance. In the results section, superscripts were used to identify
which tires were tested first. FMVSS No. 119 does not apply to speed-
restricted service and bias-ply tires, therefore those tires were not
included in the costs and benefits analysis section. The data for those
tires were collected to learn about their performance levels. Of the
365 tires tested, 159 tires were tested to the proposed methods.
Seventy-eight tires were tested for Endurance and 81 were tested for
High Speed performance.
Table 5--Phase II Tire Information
----------------------------------------------------------------------------------------------------------------
Max speed
Group No. Manufacture/model Tire size and LR (mph) Application
----------------------------------------------------------------------------------------------------------------
1.............................. Goodyear G647 RSS...... 225/70R19.5 LR F. 75 Regional/P&D
2.............................. Michelin XRV........... 225/70R19.5 LR F. 75 Long haul
3.............................. Bridgestone R293....... 11R24.5 LR G..... 75 Long haul
[[Page 60046]]
4.............................. Bridgestone M1X 711.... 11R24.5 LR G..... 75 Long haul
5.............................. General D460........... 11R24.5 LR G..... 75 Long haul
6.............................. Michelin XZY3.......... 11R24.5 LR G..... 65 Mixed service
7.............................. General S580........... 11R24.5 LR H..... 75 Long haul
8.............................. Goodyear G167.......... 11R24.5 LR H..... 75 Long haul
9.............................. Goodyear G395.......... 11R24.5 LR H..... 75 Long haul
10............................. Goodyear Marathon LHT.. 245/70R17.5 LR H. 62 N/A
11............................. Kumho 943.............. 11R24.5 LR H..... 75 Regional/P&D
12............................. Kumho KRS02............ 11R24.5 LR H..... 75 N/A
13............................. Yokohama TY303......... 11R24.5 LR H..... 75 Long haul
14............................. Yokohama RY023......... 11R24.5 LR H..... 75 Long haul
15............................. Bridgestone R184 CZ.... 215/75R17.5 LR H. 65 High Load Trailer
16............................. Bridgestone L320....... 11.00R24.5 LR H.. 65 Mixed service
17............................. Goodyear Unisteel G291. 315/80R22.5 LR J. 75 Regional/P&D
18............................. Goodyear G286 (wb)..... 385/65R22.5 LR J. 68 Mixed service
19............................. Michelin XZY3 (wb)..... 385/80R22.5 LR J. 65 Mixed service
20............................. Michelin XTA........... 215/75R17.5 LR J. 62 L. haul/Regional
21............................. Kumho KRT02............ 235/75R17.5 LR J. 62 Regional/P&D
22............................. Yokohama RY253 (wb).... 385/65R22.5 LR J. 65 Long haul
23............................. Continental HMS 45+.... 315/80R22.5 LR L. 56 Mixed service
24............................. Michelin XZUS.......... 315/80R22.5 LR L. 65 Regional/P&D
25............................. Michelin XZA2 Energy... 315/80R22.5 LR L. 75 Long haul
26............................. Milestar TRX (bias-ply) N/A LR G......... N/A N/A
27............................. Prime X Rockmaster..... N/A LR N......... N/A N/A
----------------------------------------------------------------------------------------------------------------
Note: (wb) means it is a wide-base tire; * means speed-restricted service tire.
Phase II Endurance Test
NHTSA tested new tires with load ranges F, G, H, J, L and N from
several major tire manufacturers. Table 6, ``Phase II Endurance Test
Matrix,'' shows the endurance test conditions used for Phase II
testing. These test conditions were selected based on our analysis of
the Phase I results. We varied the severity of the test conditions by
adjusting load, inflation pressure and/or speed. For each test method,
the test load was stepped-up through 85, 90, and 100 percent of maximum
load rating. Inflation pressures ranged from 80 percent to 90 percent
of maximum inflation pressure stated on the sidewall. Test speeds
ranged from 80 km/h (50 mph) to 100 km/h (62 mph). Each tire was
conditioned at ambient temperature 35 [deg]C 3 [deg]C (95
[deg]F 5 [deg]F) for three hours. All the tires were
tested for a total duration of 71 hours consisting of the 47 hours of
the current FMVSS No. 119 endurance test plus an additional 24 hours.
[[Page 60047]]
[GRAPHIC] [TIFF OMITTED] TP29SE10.008
The results of the endurance tests for new tires in Phase I
indicated that higher speeds and lower inflation pressure appear to
have the most impact on tire failure compared with changes in test load
or duration. Based on these results, in the Phase II program NHTSA
decided to moderately increase the severity of its endurance test
matrix over the current requirements in FMVSS No. 119. The least severe
test condition, Test Method 1, had the lowest test speed (80 km/h or 50
mph), and the highest inflation pressure (90 percent of maximum
inflation pressure). The most severe test condition, Test Method 6, had
the highest test speed (100 km/h or 62 mph), and the lowest inflation
pressure (80 percent of maximum inflation pressure).
Phase II Endurance Test Results
Tables 7 through 14 of this preamble, below, summarize the results
of the endurance testing in Phase II. The results indicate that as the
test severity increased, in going from Test Method 1 to Test Method 6,
tire failure rate increased. Tires tested under Test Method 1 were more
likely to achieve the target of 71 hours compared to tires tested to
Test Method 6. All of the load range G (radial) and H tires tested
under Test Methods 1 and 2 achieved the target of 71 hours, whereas
only a few of the load range G tires and none of the load range H tires
tested to Test Methods 5 and 6 were able to achieve the target of 71
hours. The dashes in the tables represent Test Methods that were not
performed for that specified tire.
Three tire groups (Nos. 10, 20, and 21) were speed-rated 62 mph.
These groups were tested with a variation in speed. Samples 1
from these three tire groups were tested at 50 mph. If sample
1 did not complete the 71-hour test, sample 2 was
tested at 45 mph and sample 3 was tested at 40 mph. If sample
1 completed the 71-hour test at 50 mph, the remaining samples
were tested at the same speed.
[[Page 60048]]
Table 7--Phase II Endurance Test Results, Load Range F
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Proposed (hours)
Tire Brands (Hours Completed)
-----------------------------------------------
Goodyear 647 RSS
Michelin XRV
-----------------------------------------------------------------------
Test Method No. Sample No.
-----------------------------------------------------------------------
1 2 3 1 2 3 1 2 3
----------------------------------------------------------------------------------------------------------------
2....................................... 47 47 47 71 71 71 71 71 71
----------------------------------------------------------------------------------------------------------------
Table 8--Phase II Endurance Test Results, Load Range G
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Tire Brands (Hours Completed)
-----------------------------------------------------------------------
Proposed (hours)
Bridgestone R293--
Steer
Bridgestone MIX 711--
Drive
General D460--Drive
-----------------------------------------------------------------------------------------------
Test Method No. Sample No.
-----------------------------------------------------------------------------------------------
1 2 3 1 2 3 1 2 3 1 2 3
--------------------------------------------------------------------------------------------------------------------------------------------------------
1....................................................... 47 47 47 71 71 71 71 71 71 ...... ...... ......
2....................................................... 47 47 47 71 71 71 71 71 71 71 71 71
3....................................................... 47 47 47 71 71 71 71 71 65 ...... ...... ......
4....................................................... 47 47 47 71 71 71 71 71 71 ...... ...... ......
5....................................................... 47 47 47 71 71 44 40 37 32 ...... ...... ......
6....................................................... 47 47 47 24 71 33 33 33 34 ...... ...... ......
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 9--Phase II Endurance Test Results, Load Range H
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Group Samples (Hours Completed)
-----------------------------------------------------------------------------------------------------------------------
Proposed (hours)
Goodyear G395--Steer
Goodyear G167--Drive
Kumho 943--Drive
Kumho KRS02--Drive
Yokohama RY023--Steer
-----------------------------------------------------------------------------------------------------------------------------------------------
Test Method No. Sample No.
-----------------------------------------------------------------------------------------------------------------------------------------------
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1............................................... 47 47 47 71 71 71 71 71 71 71 ...... ...... ...... ...... ...... ...... ...... ......
2............................................... 47 47 47 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71
3............................................... 47 47 47 41 35 50 46 69 71 ...... ...... ...... ...... ...... ...... ...... ...... ......
4............................................... 47 47 47 71 55 56 47 48 56 ...... ...... ...... ...... ...... ...... ...... ...... ......
5............................................... 47 47 47 18 19 19 24 5 27 ...... ...... ...... ...... ...... ...... ...... ...... ......
6............................................... 47 47 47 13 25 17 19 8 7 ...... ...... ...... ...... ...... ...... ...... ...... ......
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Table 10--Phase II Endurance Test Results, Load Range H
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Group Samples (Hours Completed)
-----------------------------------------------------------------------------------------------------------------------
Proposed (hours)
Goodyear Marathon LHT
Bridgestone R184 CZ
Bridgestone L320
Yokohama TY303
General S580
-----------------------------------------------------------------------------------------------------------------------------------------------
Test Method No. Sample No.
-----------------------------------------------------------------------------------------------------------------------------------------------
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
2............................................... 47 47 47 22 30 35 71 71 71 71 71 71 71 71 71 71 71 71
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Samples 2 and 3 from Goodyear LHT were tested at 45 and 40 mph.
[[Page 60049]]
Table 11--Phase II Endurance Test Results, Load Range J
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Tire Brands (Hours Completed)
-----------------------------------------------------------------------------------------------------------------------
Proposed (hours)
Yokohama RY253 (wb)--
All Pos.
Goodyear G286 (wb)--
Steer
\1\ Michelin XZY3
(wb)--All Pos.
Goodyear Unisteel G291
\2\ Michelin XZY3
(wb)--All Pos.
-----------------------------------------------------------------------------------------------------------------------------------------------
Test Method No. Sample No.
-----------------------------------------------------------------------------------------------------------------------------------------------
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1............................................... 47 47 47 71 71 71 7 4 7 71 71 71 ...... ...... ...... ...... ...... ......
2............................................... 47 47 47 71 71 71 7 5 7 65 44 71 71 71 71 71 65 71
3............................................... 47 47 47 55 45 42 2 2 5 6 70 44 ...... ...... ...... ...... ...... ......
4............................................... 47 47 47 42 43 34 ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ......
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Superscripts 1 and 2: 1 represents tires tested in 2005; 2 represents tires tested in 2008.
Table 12--Phase II Endurance Test Results, Load Range J
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Group Samples (Hours Completed)
-----------------------------------------------------------------------
Proposed (hours)
\2\ Yokohama RY253
(wb)
Michelin XTA
Kumho KRT02
-----------------------------------------------------------------------------------------------
Test Method No. Sample No.
-----------------------------------------------------------------------------------------------
1 2 3 1 2 3 1 2 3 1 2 3
-----------------------------------------------------------------------------------------------
2....................................................... 47 47 47 71 71 71 71 71 71 27 56 71
--------------------------------------------------------------------------------------------------------------------------------------------------------
Samples 2 and 3 from Kumho KRT02 were tested at 45 and 40 mph.
Table 13--Phase II Endurance Test Results, Load Range L
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Tire Brands (Hours Completed)
-----------------------------------------------------------------------------------------------------------------------
Proposed (hours)
\1\ Conti. HMS45 +
Steer
\1\ Michelin XZUS--All
Pos.
\1\ Michelin XZA2
Energy--All
Conti.HMS45 + - Steer
\2\ Michelin XZUS--All
Pos.
-----------------------------------------------------------------------------------------------------------------------------------------------
Test Method No. Sample No.
-----------------------------------------------------------------------------------------------------------------------------------------------
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1............................................... 47 47 47 19 21 20 30 28 33 ...... ...... ...... ...... ...... ...... ...... ...... ......
2............................................... 47 47 47 29 20 30 30 32 48 64 59 56 55 46.7 43 55 40 41
3............................................... 47 47 47 8 9 4 ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ......
4............................................... 47 47 47 14 14 17 ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ......
5............................................... 47 47 47 3 2 3 ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ......
6............................................... 47 47 47 4 4 3 ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ......
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Superscript 1 represents tires tested in 2005, 2 represents tires tested in 2008.
Table 14--Phase II Endurance Test Results, Load Range G Bias Ply (Trailer application) and N
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Tire Brands (Hours Completed)
-----------------------------------------------------------------------------------------------
Proposed (hours)
(G-Bias) Milestar TRX
(G-Bias) Milestar TRX
(G-Bias) Milestar TRX
(N) Prime X Rockmaster
-----------------------------------------------------------------------------------------------------------------------
Test Method No. Sample No.
-----------------------------------------------------------------------------------------------------------------------
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
--------------------------------------------------------------------------------------------------------------------------------------------------------
1............................... 47 47 47 71 71 71 71 71 70 71 71 64 5 6 4
2............................... 47 47 47 52 10 48 71 66 62 71 53 67 ...... ...... ......
3............................... 47 47 47 45 71 35 54 67 55 3 71 71 ...... ...... ......
--------------------------------------------------------------------------------------------------------------------------------------------------------
Test results also indicate that some higher load range J, L, and N
tires were overall less likely to achieve their target of 71 hours than
the load range G and H tires. Some load range J and L tires are also
used on inter-city coach buses (motorcoaches), which are operated at
highway speeds. (Tire industry data show that load range J and L tires
comprise 8 percent of the new truck tire market share (see Docket
NHTSA-2002-13707, item 18.1).) Nineteen out of the 24 (79%) load range
J tires met the proposed 47-hour test. Five out of the 9 (56%) load
range L tires tested met the proposed conditions. The load range J and
L tires we tested had speed ratings ranging from 62 to 75 mph, and all
9 tires speed-rated 75 mph met the proposed 47-hour endurance test
requirements. The agency assumes that most load range J and L tires are
speed-rated 75 mph, and that the tires would thus meet the proposed
endurance requirements. The agency is seeking comment on the percentage
of these tires that are speed-rated 75 mph.
All of the tires were not tested to every test method for several
reasons. For load range G and H tires, the
[[Page 60050]]
Bridgestone and Goodyear tires were tested to Test Method 1 through
Test Method 6. The Continental D 460, Kumho 943, Kumho KRS02, and
Yokohama RY023 tires were not tested to Test Method 1 and Test Methods
3 through 6, primarily because failures from the other groups began to
surface when tested to Test Method 3. In similar fashion, tires for
load range J, L, N, and G (bias ply), were not tested once a pattern of
failures indicated that a particular test method was beginning to
result in failures for those tires.
Phase II High Speed Test
Based on the results of the high speed tests of new tires in Phase
I,\14\ we revised the high speed test matrix for Phase II by reducing
the test speeds to speeds that are more representative of the upper
limit for heavy vehicle application. Table 15 below summarizes the test
conditions used for the high speed test in Phase II.
---------------------------------------------------------------------------
\14\ Most failures occurred in Test Method A at test speeds of
152 km/h (95 mph) or at 160 km/h (100 mph).
[GRAPHIC] [TIFF OMITTED] TP29SE10.009
We tested new tires of load ranges F, G, H, J, and L from several
major tire manufacturers. Test conditions varied in severity by
adjusting load, inflation pressure and/or speed. The applied load was
based on the single maximum load for the subject tire, stated on the
sidewall. The applied load ranged from 85 percent of maximum load
rating to 90 percent of maximum load rating. In Test Method (TM) C, the
least severe test method, the test load was set to 85 percent of
maximum load rating, and inflation pressure at 95 percent of maximum.
In the most severe Test Method (B), the load was set at 90 percent of
maximum load rating, and inflation at 90 percent of maximum. Inflation
pressures ranged from 90 percent to 95 percent of maximum pressure
stated on the sidewall. Generally, test speeds were 100/110/120 km/h
(62/68/75 mph). Each tire was conditioned at an ambient temperature of
35 [deg]C 3 [deg]C (95 [deg]F 5 [deg]F) for
three hours, broken in for two hours at 80 km/h (50 mph) under 88
percent of maximum load rating, and then run for duration of 2.5 hours.
The duration for the final speed step of 120 km/h (75 mph) was 1.5
hours, which represents an additional hour beyond the normal speed step
of 30 minutes.
Phase II High Speed Test Results
Tables 16 through 24, below, summarize the results of the high-
speed test for new tires tested in Phase II, and indicate that heavy
truck tires performed well under the test matrix of Phase II. For the
138 tires tested for high-speed durability, only 10 tires failed to
meet the set target of 2.5 hours at speed. For example, the Goodyear
Drive tire samples 1, 2, and 3 (load range H) under Test Method C,
completed 2.5, 2.4 and 2.1 hours, respectively (see Table 17).
Similarly, the same tire brand completed 2.1, 2.4 and 1.9 hours under
Test Method B. Eighty-one out of the 138 tires were tested to the
proposed high speed requirements. Ninety-nine percent (80/81) met the
1.5-hour proposed requirement, Test Method D. Several
[[Page 60051]]
tire models from Bridgestone and Goodyear tire brands were tested first
and yielded very positive results under Test Methods C and D, which
were less severe because of the lower loading conditions. Additional
tire brands (Bridgestone, Continental, Michelin, Kumho and Yokohama)
were tested to Test Methods C and D to validate the test conditions for
use in a potential upgrade for the heavy truck tire standard.
Table 16--Phase II High Speed Test Results, Load Range F
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Tire Brands (Hours Completed)
-----------------------------------------------
Target (hours)
Goodyear 647 RSS--
Steer
Michelin XRV--All Pos.
-----------------------------------------------------------------------
Test Method No. Sample No.
-----------------------------------------------------------------------
1 2 3 1 2 3 1 2 3
----------------------------------------------------------------------------------------------------------------
D....................................... 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5
----------------------------------------------------------------------------------------------------------------
Table 17--Phase II High Speed Test Results, Load Range G
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Tire Brands (Hours Completed)
-----------------------------------------------------------------------------------------------
Target Hours
Bridgestone R293--
Steer
Bridgestone MIX 711--
Drive
General D460-- Drive
Michelin XZY3
-----------------------------------------------------------------------------------------------------------------------
Test Method No. Sample No.
-----------------------------------------------------------------------------------------------------------------------
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
--------------------------------------------------------------------------------------------------------------------------------------------------------
A............................... 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 ...... ...... ...... ...... ...... ......
B............................... 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 ...... ...... ...... ...... ...... ......
C............................... 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5
D............................... 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 18--Phase II High Speed Test Results, Load Range H
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Tire Brands (Hours Completed)
-----------------------------------------------------------------------------------------------------------------------
Target Hours
Goodyear G395--Steer
Goodyear G167--Drive
Kumho 943--Drive
Kumho KRS02--Drive
Yokohama RY023--Steer
-----------------------------------------------------------------------------------------------------------------------------------------------
Test Method No. Sample No.
-----------------------------------------------------------------------------------------------------------------------------------------------
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A............................................... 2.5 2.5 2.5 2.5 2.5 2.5 1.6 2.2 1.9 ...... ...... ...... ...... ...... ...... ...... ...... ......
B............................................... 2.5 2.5 2.5 2.5 2.5 2.5 2.1 2.4 1.9 ...... ...... ...... ...... ...... ...... ...... ...... ......
C............................................... 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.4 2.1 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5
D............................................... 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.2 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Table 19--Phase II High Speed Test Results, Load Range H
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Group Samples (Hours Completed)
-----------------------------------------------------------------------------------------------
Target Hours
Goodyear Marathon LHT
Bridgestone R184 CZ
Bridgestone L320
Yokohama TY303--Drive
-----------------------------------------------------------------------------------------------------------------------
Test Method No. Sample No.
-----------------------------------------------------------------------------------------------------------------------
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
--------------------------------------------------------------------------------------------------------------------------------------------------------
C............................... 2.5 2.5 2.5 ...... ...... ...... ...... ...... ...... ...... ...... ...... 2.5 2.5 2.5
D............................... 2.5 2.5 2.5 2.3 2.5 1.6 2.5 2.5 2.5 1.3 1.8 1.8 2.5 2.5 2.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 60052]]
Table 20--Phase II High Speed Test Results, Load Range J
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Tire Brands (Hours Completed)
-----------------------------------------------------------------------
Target (hours)
Goodyear Unisteel
G291--All Pos.
Yokohama RY253 (wb)--
All Pos.
Michelin XZY3 (wb)--
All Pos.
-----------------------------------------------------------------------------------------------
Test Method No. Sample No.
-----------------------------------------------------------------------------------------------
1 2 3 1 2 3 1 2 3 1 2 3
--------------------------------------------------------------------------------------------------------------------------------------------------------
D....................................................... 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 21--Phase II High Speed Test Results, Load Range J
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Target Hours
Tire Brands (Hours Completed)
-----------------------------------------------
Michelin XTA
Kumho KRT02
-----------------------------------------------------------------------
Test Method No. Sample No.
-----------------------------------------------------------------------
1 2 3 1 2 3 1 2 3
----------------------------------------------------------------------------------------------------------------
D....................................... 2.5 2.5 2.5 2.5 2.5 2.5 2.3 2.5 2.5
----------------------------------------------------------------------------------------------------------------
Table 22--Phase II High Speed Test Results, Load Range L
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Tire Brands (Hours Completed)
-----------------------------------------------------------------------
Target Hours
Continental HMS 45+
Michelin XZUS--All
Pos.
Michelin XZA2 Energy--
All Pos.
-----------------------------------------------------------------------------------------------
Test Method No. Sample No.
-----------------------------------------------------------------------------------------------
1 2 3 1 2 3 1 2 3 1 2 3
--------------------------------------------------------------------------------------------------------------------------------------------------------
D....................................................... 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.25 2.5 2.5 2.5 2.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 23--Phase II High Speed Test Results, Load Range J, no break-in step
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Tire Brands (Hours Completed)
-----------------------------------------------------------------------
Target (hours)
Michelin XZY3 (wb)--
All Pos.
Goodyear Unisteel
G291--All Pos.
Yokohama RY253 (wb)--
All Pos.
-----------------------------------------------------------------------------------------------
Test Method No. Sample No.
-----------------------------------------------------------------------------------------------
1 2 3 1 2 3 1 2 3 1 2 3
--------------------------------------------------------------------------------------------------------------------------------------------------------
D....................................................... 2.5 2.5 2.5 2.5 2.5 2.5 1.5 2. 5 2.5 2.5 2.5 2.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 24--Phase II High Speed Test Results, Load Range L, no break-in step
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Tire Brands (Hours Completed)
-----------------------------------------------
Target (hours)
Michelin XZUS--All
Pos.
Michelin XZA2 Energy--
All Pos.
-----------------------------------------------------------------------
Test Method No. Sample No.
-----------------------------------------------------------------------
1 2 3 1 2 3 1 2 3
----------------------------------------------------------------------------------------------------------------
D....................................... 2.5 2.5 2.5 2.15 2.5 2.3 2.5 2.5 2.5
----------------------------------------------------------------------------------------------------------------
b. Summary
The results of the endurance and high speed tests indicated that
the test requirements of FMVSS No. 119 can be upgraded for radial tires
to specify more stringent, yet practicable, levels of performance that
ensure better durability in real-world applications.
Based on these test results, NHTSA proposes to upgrade the
endurance performance requirement and establish a new high-speed
performance requirement for radial tires of load ranges F, G, H, J, and
L, that are not for speed-restricted service, which comprise about 98
percent of the truck
[[Page 60053]]
tires sold in the United States.\15\ These tires are typically used for
regional haul and long haul operations and on motorcoaches. The
remaining 2 percent represent the higher load rating tires and bias ply
tires, which are more often used in mixed service (on/off-road
operations in lower speed applications), such as construction, logging,
crane, and rigging operations. However, the agency is also considering
requiring non-speed-restricted, load range M radial tires to comply
with the upgraded endurance and new high speed tests because some of
these tires are used in similar applications as load range L tires. The
agency is not proposing any new requirements for load range N tires,
which represent less than 1 percent of new tires sold and are typically
used in lower speed operations. The agency is also not proposing any
new requirements for bias ply tires, primarily because they are
typically not installed on new heavy vehicles and they represent a very
small portion of the tires sold as replacement tires. These tires would
continue to be required to comply with the current requirements. In
addition, the agency is not proposing updated requirements for light
truck tires with tread depth \18/32\ inch or greater or for speed-
restricted tires; these tires, used on light truck applications, are
load range E category, and are not the focus of this rulemaking. The
agency is not proposing any new requirements for bias ply tires,
primarily because we are not aware that they are installed on new heavy
vehicles, and we aimed at upgrading radial tires, which represent the
vast majority of the tires used on heavy vehicles.
---------------------------------------------------------------------------
\15\ New truck tire market share by load range is as follows: F-
5 percent, G-64 percent, H-23 percent, J-3 percent, L-5 percent, M
and N is less than 1 percent. See Docket NHTSA-2002-13707, item
18.1.
---------------------------------------------------------------------------
IV. Proposed Endurance Test
NHTSA is proposing to upgrade FMVSS No. 119's requirements for load
ranges F, G, H, J, and L tires that are not for speed-restricted
service by setting more stringent requirements for the endurance test.
NHTSA proposes that the endurance test be conducted using the
parameters shown in Table 25. The proposed and current endurance test
parameters may be compared as shown in Tables 25 and 26 below:
Table 25--Proposed FMVSS No. 119 Endurance Test Conditions
----------------------------------------------------------------------------------------------------------------
Inflation
Load ranges Steps Load (% Duration Speed (km/ pressure
max) (hrs) h) (% max)
----------------------------------------------------------------------------------------------------------------
1 85 7 ........... ...........
F, G, H, J, and L.............................. 2 90 16 80 80
3 100 24 ........... ...........
----------------------------------------------------------------------------------------------------------------
Table 26--Current FMVSS No. 119 Endurance Test Conditions
----------------------------------------------------------------------------------------------------------------
Load (% max)
Inflation -----------------------------------
Load ranges Speed (km/ pressure Duration (hrs)
h) (% max) -----------------------------------
7 16 24
----------------------------------------------------------------------------------------------------------------
F................................................... 64 .......... .......... .......... ..........
G................................................... 56 100 66 84 101
H, J, L, M, N....................................... 48 .......... .......... .......... ..........
----------------------------------------------------------------------------------------------------------------
A tire would comply with the proposed requirements if, at the end
of the endurance test as currently defined by the standard, there is no
visual evidence of tread, sidewall, ply, cord, inner liner, belt or
bead separation, chunking, open splices, cracking or broken cords, and
the tire pressure, when measured at any time between 15 and 25 minutes
after the end of the test, is not less than 95% of the initial test
pressure.
a. Test Speed
NHTSA proposes to raise the test speed for the endurance test to 80
km/h (50 mph) for load range F, G, H, J, and L tires, which are not for
speed-restricted service. This represents a 25 percent increase in
speed for a load range F tire, a 43 percent increase for a load range G
tire, and a 67 percent increase for load range H, J, and L tires. It is
noted that these tests are performed on a curved road wheel, a 67-inch
diameter steel drum, on which the tire being tested runs as on a
treadmill. Because the road wheel is curved, it subjects the tire to
reverse deflection compared to a tire running on a flat surface, which
makes the tire run hotter (and is therefore a more severe test).
According to American Society for Testing and Materials International
(ASTM International) research on equivalent flat-to-curved speeds based
on equivalent belt-edge temperatures, a load range G truck tire tested
on a 67-inch diameter road wheel at 85 km/h (53 mph) experiences belt-
edge temperatures similar to what a tire experiences when tested on a
flat road surface at 120 km/h (75 mph). Thus, it was determined that
the effects on the tire in the two situations will be similar, even
though the one tire is rotating at 85 km/h (53 mph) and the other at
120 km/h (75 mph). (``Phase 1--Final Report,'' ASTM Truck/Bus Tire Test
Development Task Group, 9/5/06, Docket No. NHTSA-2002-13707-10.)
In NHTSA's Phase II testing, tires were tested to speeds of 80, 90,
and 100 km/h (50, 56, and 62 mph) as potential upgrades to the current
test speeds. Only 3 of 30 tire samples were able to complete a 71-hour,
or even a 47-hour test, at 100 km/h (62 mph). At 90 km/h (56 mph), all
except three of the load range G and H tires were able to complete 47
hours. At 80 km/h (50 mph), all of the load range F, G and H tires
completed the 71-hour test without failure, even at 80 percent
inflation. Load range J tires had mixed results, and for load range L
tires, only 7 of 21 tires tested were able to complete 47 hours of the
endurance test.
Given these results, NHTSA believes that a speed of 80 km/h (50
mph) for the endurance test, when coupled with the inflation pressure
and load parameters
[[Page 60054]]
we are proposing, represents a substantial and realistic upgrade over
current requirements for commercial vehicle tires. In selecting this
test speed, we considered the maximum speed rating of the tires we
tested and those typically used in commercial vehicle applications,
including motorcoaches, and found that, according to tire manufacturer
catalogs,\16\ the majority of the tires in these usage categories were
rated at 120 km/h (75 mph). All the test tires that were rated at 120
km/h (75 mph) and some that were rated at 110 km/h (68 mph) or lower
completed the proposed 47-hour Endurance test without failure. Even
though load range J and L tires comprise only about 6 percent of the
commercial vehicle tire market, NHTSA is aware that load range J and L
tires are used on some commercial inter-city coach buses
(motorcoaches), operated on interstate highways, and their use as such
highlights the need to propose upgrading the endurance test speed for
these tires. The agency is aware that while some load range J and L
tires are rated at a maximum speed of 120 km/h (75 mph), many others
are rated at speeds between 88 km/h (55 mph) and 110 km/h (68 mph). As
a result, the agency solicits comment on the appropriateness of the 80
km/h (50 mph) test speed for load range F, G, H, J, and L tires in the
endurance test.
---------------------------------------------------------------------------
\16\ Tire catalogs were found online (www.--) at manufacturer
Web sites.
---------------------------------------------------------------------------
The agency is also considering requiring non-speed-restricted, load
range M radial tires to comply with the upgraded endurance test because
some of these wide base tires may be used in similar applications that
load range L tires are used. Given that the maximum speed rating of
these tires allows them to be used in high speed operations, possibly
instead of two lower load range tires, the agency believes that they
should be considered for inclusion in the upgrade since they could be
used in different vehicle applications than the typical speed-
restricted, load range M radial tires. Accordingly, the agency solicits
comment on requiring non-speed-restricted, load range M radial tires to
comply with the upgraded endurance test.
We are unaware of non-speed restricted, radial, load range N tires
being used in high speed operations, thus we are not proposing that
they be required to comply with this upgrade. NHTSA does not propose to
raise the endurance test speed for non-speed-restricted, load range N
tires from 48 km/h (30 mph), given their typical use on heavy vehicles,
and our concern that increasing the speed would not be practicable. Due
to their design and typical application to heavy vehicles used in mixed
(on/off-road) service at slow speeds, load range N tires performed
poorly even at the lowest test speed used by NHTSA. As stated
previously, these tires make up about 1 percent of the total market for
truck tires. NHTSA believes there is no demonstrated safety need to
upgrade these tires to comply with a more stringent endurance test,
given the typical uses of the tires.
b. Load
NHTSA proposes to change the load combination for the endurance
test to 85, 90, and 100 percent of the tire's maximum load rating, from
the 66, 84, and 101 percent combination currently required. NHTSA's
Phase II testing specified test loads at 85, 90, and 100 percent for
the same durations as currently required in FMVSS No. 119. Increasing
the first two load steps from 66 and 84 percent increased the
stringency of the first 23 hours of the proposed test, and makes them
consistent with the loads specified in FMVSS No. 139's endurance test
for light vehicle tires. NHTSA believes increasing the test load
combination from 66, 84, 101 percent to 85, 90, and 100 percent of the
tire's maximum load rating represents an overall upgrade of the loading
condition for FMVSS No. 119.
Tire failure on a vehicle in service can occur due to under-
inflation or overloading, or both. Heavy vehicle tires are used
predominantly on commercial vehicles, such as transit buses, tractor
trailer combination vehicles, and ready-mix concrete trucks, for which
loading to the vehicle's gross vehicle weight rating is typical of
normal use. Non-commercial heavy vehicles such as recreational vehicles
(motor homes) and school buses also use truck tires. Unlike passenger
cars and other light vehicles, which are rarely loaded to their maximum
vehicle weight, heavy vehicles are often used in commercial service
where the vehicle is loaded to its rated cargo or passenger load to
maximize the profitability of the vehicle's operation. Hence, the first
two steps of the proposed endurance test reflect the tire's performance
conditions at which it is expected to be used in normal service.
c. Inflation Pressure
NHTSA proposes to set inflation pressure at 80 percent of the
sidewall-labeled inflation pressure that corresponds to the tire's
maximum load rating. This represents a 20 percent decrease from the
current endurance test, which requires tires to be fully inflated. Data
from a tire pressure survey conducted by FMCSA suggests that tires on
commercial vehicles (particularly trailers) are often run under-
inflated by at least 140 kPa (20 psi).\17\ For a load range G tire,
which has a maximum inflation pressure of 760 kPa (110 psi), this level
of under-inflation represents roughly an 18 percent loss of inflation
pressure. NHTSA believes that conducting the endurance test at some
level of under-inflation instead of fully inflated better reflects
real-world conditions. NHTSA testing found that all load range G and H
tires were able to complete the endurance test at an inflation of 80
percent of maximum, even at 80 km/h (50 mph).\18\ Load range J tires,
which have a higher maximum load rating than load range G and H tires,
showed mixed results, while higher load range L and N tires experienced
failure rates at both the 90 percent and 80 percent levels of
inflation.
---------------------------------------------------------------------------
\17\ The FMCSA study, ``Commercial Vehicle Tire Condition
Sensors'' (Federal Motor Carrier Safety Administration, Nov. 2003),
looked at a total of 6,087 units and 35,128 tire samples and found,
among other things, that approximately 7 percent of the sampled
heavy vehicles have at least one tire under-inflated by 20 psi or
more.
\18\ We also note that at higher test speeds, tire performance
appears noticeably sensitive to inflation pressures. At 100 km/h,
more failures occurred at the 80 percent inflation level, and time
to failure was also shorter at that inflation level compared to 100
percent inflation.
---------------------------------------------------------------------------
NHTSA believes that testing at this level of under-inflation
represents an appropriate upgrade of the severity of the endurance test
for load range F through L truck tires. We note that the endurance
tests in the light vehicle tire standards, FMVSS Nos. 109 and 139, are
conducted with the tire under-inflated to 25 percent below its maximum
inflation pressure. NHTSA is aware that the tire industry considers 20
percent under-inflation to be essentially flat for truck tires, which
are designed to run close to their maximum inflation.
d. Duration
NHTSA proposes not to amend FMVSS No. 119's endurance test duration
of 47 hours. The current 47-hour test at 56 km/h (35 mph) results in a
distance traveled for a load range G tire of 2,632 km (1,645 miles),
and increasing the speed to 80 km/h (50 mph) increases the traveled
distance to 3,760 km (2,350 miles), a 43 percent increase in distance.
NHTSA's Phase II testing extended the endurance test duration to 71
hours so researchers could assess how long beyond the 47-hour duration
the tires were able to
[[Page 60055]]
perform. Because the failure rate did not change significantly in
testing tires beyond 47 hours,\19\ this indicates that the tires'
performance to the endurance test is less sensitive to changes in
duration than to changes in speed and inflation pressure. Thus, we
believe that extending the duration beyond the 47 hours already
required will not provide additional performance benefits.
---------------------------------------------------------------------------
\19\ When a tire failed, it generally failed well before 47
hours, rather than completing the 47 hours and then failing.
---------------------------------------------------------------------------
e. Ambient Temperature
NHTSA proposes to add a 3 [deg]C (5 [deg]F)
tolerance to the current ambient temperature specified for FMVSS No.
119's endurance test, 35 [deg]C (95 [deg]F). Tire test laboratories
benefit from an ambient temperature tolerance. The proposed 3 [deg]C (5 [deg]F) tolerance for the ambient
temperature is consistent with FMVSS No. 109 and FMVSS No. 139 in
providing a 3 [deg]C (5 [deg]F) tolerance
needed to facilitate the operations at the tire laboratories.\20\
---------------------------------------------------------------------------
\20\ In FMVSS No. 139, NHTSA requires an ambient temperature for
road-wheel testing of not less than 32 [deg]C and not more than 38
[deg]C.
---------------------------------------------------------------------------
f. Endurance Test Conclusions
The agency tentatively concludes that the proposed requirements for
the endurance test better reflect the reality of tire usage than the
current FMVSS No. 119 requirements. The proposed parameters for the
endurance test, particularly the increased test speed and the reduced
inflation pressure, reflect conditions that a heavy vehicle tire is
more likely to experience in normal service.
Based on research performed by the ASTM, a tire operated at a
highway speed of 120 km/h (75 mph) experiences an equivalent level of
stringency when tested at 85 km/h (53 mph) on a curved test wheel.\21\
We believe that the agency's proposed endurance test speed of 80 km/h
(50 mph) on the curved test wheel is therefore a realistic speed.
---------------------------------------------------------------------------
\21\ ASTM Truck/Bus Tire Test Development Task Group, Phase I--
Final Report, September 7, 2006. Available at Docket No. NHTSA-2002-
13707, Item 10.
---------------------------------------------------------------------------
The proposed inflation pressure for the endurance test is 80
percent of the maximum sidewall pressure, compared with 100 percent
currently specified in FMVSS No. 119. According to the results of
FMCSA's tire pressure monitoring survey cited above, on 6,087 heavy
vehicle units with over 35,000 tires sampled, approximately 20 percent
of the vehicles had at least one tire that was under-inflated by 20 psi
or more. As a result, testing with some level of under-inflation
reflects the reality of what heavy truck tires typically experience in
service.
The agency's testing to the proposed endurance test showed that 85
percent of all the load range F, G, H, J, and L tires tested completed
the 47-hour portion of the test, with the load range J and L tires
speed-rated less than 75 mph comprising 11 out of 12 of the failures
under 47 hours. All the load range G and H tires tested completed the
47-hour portion of the test without any failures. However, even though
the load range G and H tires met the proposed requirements when tested
for a duration of 47 hours, NHTSA expects that some manufacturers of
load range G and H tires may make some design changes to these tires to
maintain an adequate margin of compliance. We expect that design
changes will be needed for some load range J and L tires, particularly
those with a maximum speed rating lower than 120 km/h (75 mph), to
enable them to comply with the proposed Endurance test requirements at
80 km/h (50 mph). The agency seeks comments on the appropriateness of
the proposed endurance test parameters for these tires.
V. Proposed High Speed Test
In its tire testing program, NHTSA performed high speed tests on
load range F, G and H tires because these are the ones predominantly
used on commercial vehicles and are the most likely of all higher load
range tires to be operated at the speed conditions proposed for this
test. NHTSA performed high speed tests on load range J and L tires even
though the tires have a small market share (about 8 percent), because
some of these tires have a maximum speed rating of 75 mph and are used
on motorcoaches.\22\ NHTSA did not perform high speed tests on speed-
restricted load range M or N tires, because we were aware that these
tires are not typically operated at these speed conditions. After
careful review of the testing results and of the information on the use
of load range J and L tires on coach buses, NHTSA proposes to include
in FMVSS No. 119 a high speed test for load range F, G, H, J, and L
tires, that are not for speed-restricted service. In addition, the
agency is also considering requiring non-speed-restricted, load range M
radial tires to comply with the upgraded endurance and new high speed
tests because some of these tires are used in high speed operations.
Bias ply and load range N tires that are for speed restricted-service
would not be subjected to a high speed test.
---------------------------------------------------------------------------
\22\ The same size tire can become a load range G, H, or J tire
depending on its construction and on its inflation pressure (e.g.,
for a 315/80R22.5 tire, the maximum load rating (3,750 kg or 8,270
lbs) for the load range J tire is achieved at an inflation pressure
of 830 kPa (120 psi), and the maximum load rating (3,450 kg or 7,610
lbs) when used in the load range H application is achieved at an
inflation pressure of 760 kPa (110 psi)). A comparison of the load/
inflation pressure values in the 2007 Tire and Rim Association Year
Book for the proposed high-speed test conditions (85 percent of
maximum load rating, 90 percent of maximum inflation pressure)
indicates that the tires are well within the load limits specified
for the test inflation pressure. For the tire size example used
above, the test load for a load range J tire would be 3,188 kg or
7,030 lbs (85 percent of maximum load rating) and the test inflation
pressure would be 747 kPa (108 psi), which is well above the
inflation pressure of 670 kPa needed to support that test load
according to the Year Book.
---------------------------------------------------------------------------
NHTSA proposes that the high speed test would be initiated after a
2-hour break-in at 80 km/h (50 mph) and 85 percent of maximum load
rating, with inflation pressure at 90 percent of maximum. The break-in
procedure conditions a new tire for testing since it exercises the tire
components and increases the tire temperature, which results in some
growth in the rubber components of the tire. This tire growth results
in a slight decrease in the tire's inflation pressure at the end of the
break-in period and leads to less growth and negligible pressure
decrease at the end of the 90-minute high speed test.
There is currently a high speed test in FMVSS No. 119, but it
applies only to motorcycle tires and to non-speed-restricted tires with
a rim diameter code of 14.5 or less marked load range A, B, C, or D.
Therefore, heavy vehicle tires with a load range of F or above have not
been required to meet the high speed test requirements in the current
standard. Table 22 shows test parameters for the proposed high speed
test.
[[Page 60056]]
Table 27-High Speed Test Conditions
----------------------------------------------------------------------------------------------------------------
Inflation
Load ranges Steps Speed (km/ Duration Load (% pressure
h) (minutes) max) (% max)
----------------------------------------------------------------------------------------------------------------
Break-in 80 120 85 90
F, G, H, J, and L................................... 1 Max--20 30 .......... ..........
2 Max--10 30 85 90
3 Max 30 .......... ..........
----------------------------------------------------------------------------------------------------------------
A tire would comply with the proposed requirements if, at the end
of the high speed test, there is no visual evidence of tread, sidewall,
ply, cord, inner liner, or bead separation, chunking, open splices,
cracking, or broken cords,\23\ and the tire pressure, when measured at
any time between 15 and 25 minutes after the end of the test, must not
be less than 95% of the initial test pressure. Load range M tires are
not included in the high speed test table but the agency seeks comments
on whether those non-speed-restricted, radial tires, should be required
to comply with the new proposed high speed test requirements. We are
unaware of non-speed restricted, radial, load range N tires being used
in high speed operations, thus we tentatively conclude that they not be
required to comply with this upgrade.
---------------------------------------------------------------------------
\23\ We note that all of these terms are defined in the current
standard.
---------------------------------------------------------------------------
a. Test Speed and Break-In Procedure
NHTSA proposes to set the test speed for the high-speed test at the
tire's maximum speed less 20 km/h (12 mph) for step 1, maximum speed
less 10 km/h (6 mph) for step 2, and at maximum speed for the final
step. This approach is similar to the approach used by the United
Nations Economic Commission for Europe (ECE) tire Regulations, which
establish tire test speeds based on the maximum rated speed of the
tire. It is also consistent with RMA's suggestion to the agency that
tires should only be tested for high speed performance up to their
maximum speed rating.\24\ We are proposing this approach, instead of
establishing one set of test speeds as a minimum requirement for all
tires as we have done for motorcycle and passenger car tires, because
unlike motorcycle and passenger car tires, heavy vehicle tires are
designed for a wide range of applications and have a narrow range of
maximum speed ratings.
---------------------------------------------------------------------------
\24\ Docket No. NHTSA 2002-13707-0016.1.
---------------------------------------------------------------------------
The truck tires for which we are proposing a high speed test in
FMVSS No. 119 have speed ratings ranging only from 100-120 km/h (62-75
mph), which are typical operating speeds for the heavy vehicles on
which these tires are installed. If one set of test speeds were applied
to these tires regardless of the speed rating, a tire speed rated at
the lower end of the range could be subjected to test speeds above the
speed rating of the tire, which could be inappropriate. (An example of
this situation is a tire speed rated to 62 mph tested at a speed of 75
mph.) Conversely, subjecting a tire that is speed rated at the higher
end of the range to a test speed substantially below the speed rating
of the tire might under-test the tire and fail to evaluate its high
speed performance. Therefore, we are proposing to establish test speeds
based on the tire's speed rating because we believe that it results in
a high speed test that better reflects the limits of the tire's
performance.
However, we disagree with RMA's suggestion that the high speed test
procedure should exclude the break-in step, which is normally the first
step when conducting a high speed test. The regulatory text of this
NPRM does not remove the break-in step from the procedure but we are
soliciting comments on whether it is appropriate to do so. The agency's
tire testing included a break-in step and we plan to gather additional
data on tires tested without the break-in step to determine whether
there is a difference in the tire's performance.
We have tentatively decided to retain the break-in step because the
step helps to condition the rubber components of new tires through
initial flexing that allows the tire to expand and grow prior to
testing. As a result, tire growth is minimized during the test, which
in turn minimizes the decrease of the test pressure at the end of the
test. Further, the high speed test for light vehicle tires has a break-
in step. When we issued the upgraded light vehicle tire standard in
2003, the agency included the tire break-in procedure in FMVSS No.
139's high speed test procedure with the support of the tire industry
(68 FR 38151). Since the high speed test proposed today would be a new
test for heavy vehicle tires, we are proposing to adopt a break-in
procedure similar to that of light vehicle tires. As noted above, Phase
II high speed testing included the break-in step to evaluate high speed
performance, testing that involved testing most tires above their
maximum speed rating.
Phase II testing used test speeds of 100, 110, and 120 km/h (62,
68, and 75 mph). The truck tires tested (load range G and H) performed
well, and most were able to complete the 2.5-hour target duration
without failure. All except one of the tires tested to the high-speed
test in Phase II completed the first 1.5 hours without failure.
The agency solicits comments on the performance of tires to a high
speed test, and is particularly interested in the performance of load
range J and L tires. We are aware that while some load range J and L
tires have maximum rated speeds at 120 km/h (75 mph), some are rated
below that speed. Further, according to Tire and Rim Association
Yearbook, manufacturers may recommend that tires may be used at speeds
higher than the tire manufacturer's rated speed if the load and
pressure are adjusted. As a result, the agency seeks comment on the
appropriateness of the test speeds for load range F, G, H, J, and L
tires in the high speed test. The agency tentatively concludes that a
high speed test at the proposed test speeds represents an important and
practicable improvement to FMVSS No. 119 in the safety requirements of
load range F, G, H, J, and L tires that are not for speed-restricted
service.
In addition, the agency is considering requiring load range M tires
speed rated 75 mph to comply with the high speed test because some of
these wide base tires may be used in similar applications load range L
tires are used. Given that the maximum speed rating of these tires
allows them to be used in high speed operations, possibly instead of
two lower load range tires, the agency believes that they should be
considered for inclusion in the upgrade since they could be used in
different vehicle applications than the typical load range M and N
tires. Accordingly, the agency seeks comment on the appropriateness of
requiring load range M tires speed rated 75 mph to comply with the high
speed test.
[[Page 60057]]
b. Load
NHTSA proposes to set the test load for the high speed test at 85
percent of the maximum load rating for the tire. NHTSA's testing
specified test loads at 85 and 90 percent. Most tires tested were able
to complete the 90 percent load rating application without any
failure,\25\ and additional tire types tested to 85 percent load were
also able to complete 1.5 hours without failure.
---------------------------------------------------------------------------
\25\ However, the Goodyear brand drive axle tire appeared
sensitive to load, as it failed more at 90 percent load. The failure
of these tires to reach the test target of 2.5 hours duration raised
some concerns that other drive axle tires with lug-type treads may
not pass at 90 percent load.
---------------------------------------------------------------------------
We chose to select a different load for the high speed test so as
not to duplicate the load conditions used in the endurance test. The
recent update of the high speed test in the FMVSS No. 139 specifies a
test load of 85 percent of the tire's maximum load rating. NHTSA
tentatively concludes that a test load of 85 percent of the maximum
load rating of the tire will provide a necessary improvement, while
setting a realistic level of performance for load range F, G, H, J, and
L tires that are not for speed-restricted service.
c. Inflation Pressure
NHTSA proposes that the high speed test inflation pressure be set
at 90 percent of the sidewall-labeled inflation pressure that
corresponds to the tire's maximum load rating. For Phase II testing,
NHTSA researchers selected inflation pressures of 90 and 95 percent to
assess the tire's high-speed performance at slight levels of under
inflation. The high speed test in the light vehicle tire standards,
FMVSS Nos. 109 and 139, is conducted with the tire under inflated to
about 8 percent below its maximum inflation pressure. Therefore, for
this Phase II testing, inflation pressures of 5 and 10 percent below
maximum were considered reasonable levels. Inflation test pressures in
this range, with a test load of 85 percent, do not result in the tire
being overloaded for the given inflation pressure. Based on the test
results where only 10 out of 102 tires were unable to finish the 150
minute test, NHTSA proposes that the high speed inflation pressure be
set at 90 percent of the sidewall-labeled inflation pressure that
corresponds to the tire's maximum load rating per sidewall labeling.
d. Duration
NHTSA proposes a 90-minute duration for FMVSS No. 119's high speed
test, to be applied to load range F, G, H, J and L tires, that are not
for speed-restricted service. The current duration for the high speed
test in FMVSS Nos. 119 and 139 is 90 minutes, consisting of three 30-
minute speed steps. High speed tests are typically of relatively short
duration, given that the purpose of the test is to assess the tire's
performance close to its upper design limit of speed. Overall, 90
percent of the test tires performed well at the 100, 110, and 120 km/h
(62, 68, and 75 mph) speeds, and were able to complete 90 minutes of
the test without any failures.\26\ Therefore, NHTSA proposes to extend
FMVSS No. 119's high speed test to apply to load range F, G, H, J and L
tires, that are not for speed-restricted service, with a total 90-
minute duration.
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\26\ NHTSA's Phase II testing extended the high-speed test to
2.5 hours to assess the limits of performance based on current truck
tire technology, but not specifically with the aim of developing a
proposal for a longer high-speed test.
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e. Ambient Temperature
NHTSA proposes an ambient temperature range of 35 [deg]C 3 [deg]C (95 [deg]F 5 [deg]F) for the FMVSS No. 119
high speed test upgrade. The ambient temperature specified for FMVSS
No. 119's high-speed test is currently 35 [deg]C (95 [deg]F) without
any temperature tolerance. Because an ambient temperature tolerance
provides test laboratories with needed flexibility, we propose
specifying a 6 [deg]C tolerance for the ambient temperature instead of
a single temperature. The agency tentatively concludes that this
proposal for FMVSS No. 119's high speed test is reasonable and
appropriate.
VI. Tire Maximum Speed Marking
FMVSS No. 119 currently requires certain information to be marked
on the tire sidewall. S6.5(d) of the standard requires that each tire's
maximum load rating for single and dual applications and the
corresponding inflation pressure be labeled on the sidewall, which
provides information to the vehicle operator to ensure proper selection
and use of tires. These load and inflation pressure values are also
used by NHTSA to determine test values for compliance testing purposes.
The tire's maximum speed rating is currently not required to be
labeled on the sidewall,\27\ except for tires that are speed-restricted
to 90 km/h (55 mph) or below. For speed-restricted tires, S6.5(e) of
the standard requires that the label on the sidewall be as follows:
``Max Speed ---- km/h (---- mph).'' \28\ For tires that are not speed-
restricted, the end user does not know from the tire sidewall labeling
the design maximum speed capability of the tire for the specified
maximum load rating and corresponding inflation pressure. We believe
that having the maximum speed rating labeled on the sidewall would
benefit the end user, especially as the speed capability in any one
load range can vary.
---------------------------------------------------------------------------
\27\ Currently the maximum speed ratings for most tires are
listed only in tire manufacturers' catalogs. Some tire manufacturers
identify their tires by maximum speed, maximum speed limit, or
allowable speed range, while others may not publish the speed
capability of their tires. Common maximum speed ratings for tires
found in catalogs are 50, 56, 60, 62, 65, 68, 70, 75, and 81 mph.
\28\ Tire manufacturers currently may include the speed rating,
voluntarily, for tires that are not speed restricted to 90 km/h or
less.
---------------------------------------------------------------------------
As such, the agency is proposing a requirement for a maximum speed
rating label for radial truck tires with load ranges F and above. The
agency is proposing the same speed labeling format as the one described
in S6.5(e)--which requires each tire to be labeled, ``Max Speed ----
km/h (---- mph)''--subject to aspects discussed below. The agency
believes that a maximum speed label that includes a numerical value
would be less subject to misunderstanding by consumers.
Numerical Value Versus a Symbol
We are aware that some tire manufacturers now voluntarily label the
non-speed restricted heavy vehicle tires they sell in the U.S. with
speed restrictions that use a different format, i.e., speed symbols, to
indicate the tire's speed.\29\ For heavy vehicle tires, the speed
symbols and the corresponding speed category used internationally are:
F--80 km/h (50 mph); G--90 km/h (55 mph); J--100 km/h (62 mph); K--110
km/h (68 mph); and L--120 km/h (75 mph). We have tentatively determined
that the speed symbol format is less desirable than labeling the tire
with a numerical value, because the consumer is more likely to
understand the meaning of the latter than that of a letter symbol.
Further, the letter format could be lead to confusion given that the
current load range label required on heavy vehicle tires uses a similar
lettering scheme (load ranges F, G, H, J, L, M and N) that includes
letters that are identical in some instances to the speed symbols used
on heavy vehicles (speed symbols F, G, J, K, and L). The corresponding
speed for these speed symbols are typically listed in the industry
publications such as the annual Year Book of the Tire and Rim
Association or the Japan Automobile Tyre Manufacturers Association.
---------------------------------------------------------------------------
\29\ As discussed later in this preamble, the Rubber
Manufacturers Association has suggested to NHTSA that the agency
require all radial tires with a load range of F and higher (that are
not speed restricted) be labeled with a service description
identified by an international labeling system.
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[[Page 60058]]
We recognize that many large trucking fleets work closely with tire
dealers, who have ready access to the industry publications and who
recommend the best tires for the fleets based on vehicle use and in-
service conditions. However, since many of the small fleets and owner-
operated fleets make their own tire purchasing decisions without such
help, labeling that is clear and easy to understand (the numerical
value) should help users purchase the appropriate tires for their
vehicles, know the speed restrictions of the tire, and use the tires in
accordance with those speed restrictions.
Multiples of 10 km/h
We propose to require that manufacturers must label their tires
with maximum rated speeds in multiples of 10 km/h (e.g., 100, 110, or
120 km/h). The proposed new high speed test specifies test speeds that
are multiples of 10 km/h: the test speed for the high-speed test would
be the tire's maximum speed less 20 km/h (12 mph) for step 1, the
tire's maximum speed less 10 km/h (6 mph) for step 2, and at maximum
speed for the final step. NHTSA believes that compliance testing for
High Speed performance would be conducted more efficiently and be less
subject to test-speed problems, if the markings are in multiples of 10
km/h.
Terminology
We note that some manufacturers use the term ``Maximum Speed'' in
their tire catalogs, while others use ``Speed Rating.'' We seek comment
on whether ``Speed Rating'' should be used on the label, instead of or
in addition to ``Max Speed.''
VII. Other Issues
a. Alternatives Considered
1. International Standards
The ECE regulation that is applicable to truck tires is ECE
Regulation 54, Uniform Provisions Concerning the Approval of Pneumatic
Tyres for Commercial Vehicles and Their Trailers. It applies to both
heavy truck tires and light truck tires, as was the case for FMVSS No.
119 prior to the establishment of FMVSS No. 139. It includes a load/
speed endurance test that is similar to the existing FMVSS No. 119
endurance test for medium/heavy truck tires. The test parameters for
load, inflation pressure, and duration are identical to those specified
in FMVSS No. 119, except for the ambient temperature, which is
specified at 25 [deg]C 5 [deg]C, compared with the
specification of 35 [deg]C 3 [deg]C as proposed for the
revision to FMVSS No. 119. The other difference between the two
standards is that ECE Regulation 54 uses the tire's speed category to
determine its test speed, whereas FMVSS No. 119 uses the tire's load
range to determine its test speed. The test speeds in ECE Regulation 54
are approximately 48-56 km/h (30-35 mph) lower than the maximum speed
rating of the tire, which results in test speeds that are in a speed
range not very much different from the test speed required in FMVSS No.
119 for non-speed-restricted tires. Test speeds in ECE Regulation 54
range from 32-72 km/h (20-45 mph) whereas the Endurance test speeds in
FMVSS No. 119 range from 48-64 km/h (30-40 mph). Hence, the severity of
the ECE regulation for heavy vehicle tires is about the same as for
tires under the current FMVSS No. 119. Additionally, the ECE has no
high speed test for truck tires. In short, ECE Regulation 54 contains
test parameters and performance requirements that are, in some cases,
similar to the current FMVSS No. 119, but that we believe are in other
cases less stringent.
The agency is not aware of other truck tire standards that are
different from ECE Regulation 54 or FMVSS No. 119, since many national
regulations typically adopt some version of the ECE regulation or the
FMVSS.
2. ASTM Truck/Bus Tire Test Development Task Group
The ASTM Truck/Bus Tire Test Development Task Group recommended
that the agency consider the artificial stresses and temperature
impacts that are introduced into tire testing when tires (particularly
medium truck tires and larger) are tested on a 67-inch diameter test
road-wheel, as compared to a flat surface. The task group has been
working to develop a tire temperature prediction model for two critical
crown area temperatures, tread centerline and belt edge, based on
comparisons of tire temperatures obtained from tests of five load range
G tires \30\ on a 67-inch diameter curved road wheel, on a flat track
test surface, and on an outdoor test track. (``Phase 1-Final Report,''
ASTM Truck/Bus Tire Test Development Task Group, 9/5/06, Docket No.
NHTSA-2002-13707-10. ``Phase I & II Review,'' ASTM Truck/Bus Tire Test
Development Task Group, 5/15/08, Docket No. NHTSA-2002-13707-14.) As a
result of this work, the task group found that, for the five load range
G tires it tested: (a) The average predicted temperature increases an
average of 39 [deg]C (70 [deg]F) at the tread centerline and 22 [deg]C
(40 [deg]F) at the tire's belt edge when tested on a 67-inch diameter
curved road-wheel as compared to temperatures obtained from tires
tested on a flat surface; (b) equivalent tread centerline temperatures
were obtained between tires tested on a curved road-wheel at 67 km/h
(42 mph) and tires tested on a flat roadway surface at 120 km/h (75
mph); and (c) equivalent tread belt edge temperatures were obtained
between tires tested on a curved road-wheel at 79 km/h (49 mph) and
tires tested on a flat roadway speed at 120 km/h (75 mph). The task
group recommended that NHTSA develop a standard based on maintaining
equivalent tire crown area temperatures (i.e., centerline, shoulder,
and belt edge) between flat and curve test surfaces.
---------------------------------------------------------------------------
\30\ The test tires, from Bridgestone, Goodyear, and Michelin,
included three drive axle tires with a tread depth of 30/32 inch;
one steer axle tire with a tread depth of 18/32 inch; and one
trailer axle tire with a tread depth of 12/32 inch.
---------------------------------------------------------------------------
It should be noted that in 2008, the Task Group also completed a
Phase II, which included load range J and L tires to validate the
applicability of the truck tire test conditions to additional tire
sizes and service applications such as inter-city buses and refuse
trucks and ready mix cement trucks. ASTM concluded from the results of
Phase II that for tires with a maximum speed rating below 120 km/h (75
mph) the Endurance test speed should be reduced from 80 km/h (50 mph)
to 72 km/h (45 mph).
NHTSA is aware that a tire operated on a curved road-wheel,
compared to a tire operated on a flat road surface, experiences higher
centerline and belt edge temperatures due to several factors, e.g.,
severe reverse curvature at the tire contact patch; distortion of the
tire contact patch shape; and over-deflection of the tire sidewall.
NHTSA's tests are conducted on a curved road-wheel. There appears to be
several anomalies in the results from the ASTM model, such as the
centerline temperatures being higher for the 18/32-inch tread depth
tire compared with the centerline temperatures for the 30/32-inch tread
depth tire. (A tire with a greater tread depth generally runs hotter
than one with a lower tread depth.) There are also test conditions
where the model predicted lower tire temperatures when tested on the
road-wheel than the tire temperatures when tested on the flat track
machine and the test track. In addition, the test duration for the
tires the task group tested was limited to 60 minutes to achieve a
steady-state temperature, which does not reflect the level of
stringency a tire experiences during a 47-hour test as performed under
the current FMVSS No. 119 endurance test.
[[Page 60059]]
Nevertheless, we note that our rulemaking proposal to upgrade the
endurance test includes parameters that are on the same order of
magnitude as those provided in the task group's recommendations. Our
proposal includes an endurance test speed of 80 km/h (50 mph) on a
curved road-wheel, up to 100 percent maximum load rating, 80 percent of
the maximum inflation pressure, and 35 [deg]C (95 [deg]F) ambient
temperature. From the results in our Phase II endurance and high-speed
tests, we tentatively believe that these parameters are reasonable and
practicable and consistent with the task group's recommendation.
3. Rubber Manufacturers Association
On May 14, 2009, RMA submitted information to the agency regarding
an upgrade of FMVSS No. 119 (see Docket No. NHTSA 2002-13707-0016.1
(RMA Perspective on the FMVSS 119 Revisions and Updates Mandated by the
TREAD Act)). RMA's information included suggestions for a number of
matters regulated by FMVSS No. 119, including the endurance and high
speed tests, and had data from tests it had conducted (although from
only one manufacturer). The suggestions are briefly described below.
RMA suggested that NHTSA mandate that all radial tires with a load
range of F and higher (that are not for speed-restricted service) be
labeled with a service description identified by an international
labeling system, in support of global harmonization and that it be used
as the basis for testing.\31\ RMA suggested that the endurance test
speed in the upgraded FMVSS No. 119 be based on that speed symbol. RMA
suggested that tires with speed symbols of J, K, L, and M be tested at
a speed equal to the difference between the speed symbol and 40 km/h
(25 mph). If the tire has a speed symbol L, which deciphered is a speed
rating of 120 km/h (75 mph), the endurance test speed would be 80 km/h
(50 mph), or if a tire has a speed symbol J, which deciphered is a
speed rating of 100 km/h (62 mph), the endurance test speed would be 60
km/h (37 mph).
---------------------------------------------------------------------------
\31\ The corresponding values for the maximum load and speed
symbols of that labeling system may be found in literature published
by entities such as: Tire & Rim Association, European Tyre and Rim
Technical Organization, Japan Automobile Tyre Manufacturers
Association, and others.
---------------------------------------------------------------------------
RMA suggested that if a high speed test is adopted in FMVSS No.
119, the test should be a stepped-up speed test with three 30-minute
steps. The test speeds RMA suggested would be indexed to the
corresponding speed symbol of the tire (i.e., step 1 test speed is 20
km/h below the speed symbol, step 2 test speed is 10 km/h below the
speed symbol, and step 3 test speed is run at corresponding speed for
that symbol). Further, RMA believed that the high speed test should be
conducted without the initial break-in step. According to RMA, there
are data supporting that the tire growth during the break-in step was
negligible, and that the step was thus unnecessary.
Test conditions such as inflation pressure, load, duration, and
ambient temperature in RMA's suggested tests (endurance and high speed)
would be the same as NHTSA's proposed test conditions. Other issues
discussed by RMA may be found in the docket submission.
Some of RMA's suggestions have been incorporated into this NPRM. As
discussed above, NHTSA has proposed requiring tires to have a maximum
speed rating label on their sidewalls so that users will know a tire's
maximum speed capability. Thus, a labeling proposal in included in this
NPRM. However, as explained above, the agency believes that using an
international labeling system to identify the tire's maximum load and
speed ratings would not benefit end users in the U.S. because the
literature used to reference these values may not be readily available
for all users, and because the lettering system may be confusing.
Accordingly, the NPRM proposes that a numerical value be labeled rather
than a symbol.
This NPRM incorporates RMA's suggestion that a high speed test
should comprise a stepped-up speed test with three 30-minute steps
using test speeds indexed to the corresponding speed rating of the
tire. However, as explained earlier in this document, this NPRM does
not propose RMA's suggestion to remove the break-in step from the high
speed test but we are soliciting comments on whether it is appropriate
to do so.
With regard to RMA's suggestion about the endurance test, at this
time the agency does not believe that all tires should be tested to 40
km/h (25 mph) less than the tire's maximum speed rating in the
endurance test. RMA used research findings from the ASTM as a basis for
the suggestion to establish the test speeds. ASTM found that there was
an equivalence in belt edge temperatures for tires tested on a flat
road surface at 120 km/h (75 mph) and on a curved road wheel at 80 km/h
(50 mph). Hence, this 40-km/h (25-mph) differential was used by RMA in
its recommendations for the test speeds NHTSA should propose for the
endurance test.
The RMA test data used to support its recommendations was limited,
generated from only one of its members, Bridgestone Firestone. Also,
the mix of tires in the RMA data did not reflect the real-world mix of
heavy vehicle tires sold in the U.S. Although the ASTM findings appear
to support the finding that a 40-km/h (25-mph) differential exists in
test speeds in the 120-km/h (75-mph) range, NHTSA does not have enough
information to conclude that these findings can be extrapolated to
include speeds much lower than 120 km/h (75 mph). The agency is
currently reviewing data from lower speed rated tires 100 km/h (62
mph). We request data from tire manufacturers on the performance of
lower speed rated tires, particularly for the proposed endurance test,
and comments from the public on RMA's submission to the docket.
We believe that the NPRM's proposed test conditions for the
endurance test are practicable and reasonable and reflect our
recognition of the severity of the endurance test on the curved road
wheel.\32\ Our data show that some tires that are speed rated 65 mph
were able to meet the proposed endurance test when tested to 80 km/h
(50 mph). The vast majority of the tires we tested completed the
proposed 47-hour endurance test at 80 km/h (50 mph) without failure.
---------------------------------------------------------------------------
\32\ The endurance test is a more stringent test than the high
speed test, primarily because of the lower inflation pressure and
longer duration specified for the test.
---------------------------------------------------------------------------
b. Deep Tread Truck Tires
The agency tested tires with tread depths that are typical of on-
road service, and included drive axle tires with tread depths of about
30/32 inch, steel axle tires with tread depths of about 18/32 inch, and
trailer tires with tread depths around 12/32 inch. We are aware that
there are deep tread truck tires with a load range of H, J, or L that
have tread depths greater than 32/32 inch, but none of these tires was
included in our testing because they appear to represent a very small
percentage of heavy truck tires. We are soliciting public comments on
the applicability of the proposed endurance and high speed requirements
to deep tread truck tires and welcome test data submissions for the
docket.
c. Correction of Table III
In Table III, ``Endurance Test Schedule,'' of FMVSS No. 119, there
are several minor items of information that have been inadvertently
omitted from the table over the course of years of amendments to the
standard, most recently when the standard was
[[Page 60060]]
amended on June 26, 2003. The Table III proposed in today's NPRM
corrects those omissions, by including for tires described as ``All
other,'' a row for load range A, B, C, and D tires, and a row for load
range E tires, which include bias-ply tires and others not covered
under FMVSS No. 139. Footnote text has also been added to correspond to
the footnote superscripts 1 and 2. In addition, the current Table III
does not include load range C and D for speed-restricted service and
load range M on the list of tires for non-speed-restricted service but
it does include load range N, which is a higher load range tire. Load
range C and D were inadvertently excluded from Table III. Also, load
range M has been inadvertently excluded from Table III since both load
range M and N tires are included in the list of speed-restricted tires
required to comply with FMVSS No. 119. The agency seeks comments on
including load range M on the list of non-speed-restricted tires
covered under the standard. In addition, we are proposing to change the
superscript format from numerical values 1 and 2 to alphabet letters A
and B to enhance clarity. We are also seeking comments on this issue.
d. Separate Standard
We note for the reader that, assuming we issue a final rule on this
subject, the final rule might separate the non-speed-restricted, radial
tires of load ranges F, G, H, J, and L, from the requirements currently
in FMVSS No. 119 that this NPRM does not propose to upgrade. We might
set forth the upgraded requirements for the non-speed-restricted,
radial tires of load ranges F, G, H, J, and L, in a new standard to
make clear the regulatory language between those tires whose
requirements were not upgraded. The agency took the same approach when
it upgraded tires for vehicles with a GVWR of 4,536 kg (10,000 lb) or
less, establishing FMVSS No. 139. RMA has also endorsed this approach
in its letter to the agency; see Docket No. NHTSA 2002-13707-0016.1, p.
13.
VIII. Proposed Effective Date
NHTSA proposes that the proposed requirements for load range F, G,
and H tires be effective two years after publication of a final rule.
The results of the tire research indicate that most load range G and H
tires are able to meet the proposed requirements with little if any
modification. Load range J tires might need some design changes to
comply with the upgraded requirements. Given the need for modification
and the small market share of the tires, the agency proposes an
effective date of three years after publication of a final rule for
load range J and L tires. In addition, the agency's proposal to
establish new labeling requirements for the maximum speed rating of the
tire would require changes in some tire molds. We propose that the new
maximum speed rating labeling requirements for load range F, G, H, J,
and L tires be effective 5 years after the publication of the final
rule. NHTSA requests comment on the proposed lead time for meeting the
performance requirements and the labeling requirements.
IX. Costs and Benefits
According to Modern Tire Dealer, the 2008 sales for medium and
heavy truck original equipment and replacement tires were 4.3 million
and 15.5 million, respectively. Comments are requested on the number of
tire sales by all (F, G, H, J, and L) load ranges and speed ratings.
All of the G load range tires tested passed the proposed criteria.
Also, all of the H load range tires tested, except for one brand speed
rated at 62 mph, passed the proposed criteria. For the endurance test,
of the six J load range brand/models tested, all three tires from three
brand/models passed, two of three from a fourth brand/model passed,
none of a fifth brand/model passed, and three tires from a sixth brand
passed. Costs to bring the H and J load range tires into compliance
with the proposal are not anticipated to be greater than $15 per tire.
Out of the fifteen load range L tires tested (three tires for each
of five brand/models), only seven tires passed the proposed test and
two did so with a small margin based on the proposed 47 hours duration
for the endurance test. Comments are requested on the technology needed
and cost to make other load range L tires pass the proposed endurance
test. At one end of the cost spectrum, improved rubber compounds could
be a countermeasure that could reduce heat retention with costs at
about an additional $0.25 per pound. Since these tires have about 100
pounds of rubber this would add $25 in costs to each L load range tire.
At the other end of the cost range, one could assume these tires need
to be made significantly lighter to pass the test with better
materials. This would entail using ultra high tensile strength steel
costing an additional $2 per pound. Those tires now have 35 pounds of
steel in them, totaling $70. Combining these two methods could add up
to $95 per tire (these tires typically cost about $525 each). Comments
are also requested on the costs associated with the new speed labeling
requirement.
As discussed above, the costs to bring load range H, J and L tires
to compliance with the proposed requirements are estimated to range
from $15 to $95 per tire. The combined H, J, and L load range tire
sales comprised about 29 percent of the total medium and heavy truck
tire sales (19.8 million tires). Of the 29 percent, about 23 percent or
4,554,000 are believed to be H load range tires, about 3 percent or
594,000 are believed to be J load range tires, and about 3 percent or
594,000 to be L load range tires. There are an estimated 227,700 sales
for H load range tires, 118,800 sales for J load range tires and
118,800 sales for L load range tires, all with a speed rating of 62, 65
or 68 mph. Applying the failure rate and cost per tire to the estimated
sales of H, J and L load range tires with a speed rating of 62, 65 or
68 mph would result in a total cost of $13,314,362.
NHTSA believes that this NPRM has a beneficial effect on safety in
that it would ensure greater tire durability as tires are held to more
stringent standards than currently required. However, the agency has
limited data on the crashes in the crash databases related to tires in
these load ranges. Comments are requested on the different applications
of various speed rating and load range tires (e.g., over the road bus
operations, etc.).
X. Rulemaking Analyses and Notices
Executive Order 12866 and DOT Regulatory Policies and Procedures
This rulemaking document was not reviewed by the Office of
Management and Budget under E.O. 12866. It is not considered to be
significant under E.O. 12866 or the Department's Regulatory Policies
and Procedures (44 FR 11034; February 26, 1979). This document proposes
upgrades to FMVSS No. 119 that we believe most tire manufacturers will
be able to meet without substantial difficulty. NHTSA has prepared a
regulatory evaluation that discusses the costs and other impacts of
this proposed rule.\33\
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\33\ The evaluation may be obtained by contacting Docket
Management at the address or telephone number provided at the
beginning of this document. You may also read the document via the
Internet, by following the instructions in the section below
entitled, ``Public Participation.'' The evaluation will be listed in
the docket summary.
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NHTSA believes that this NPRM has a beneficial effect on safety in
that it would ensure greater tire durability as tires are held to more
stringent standards than currently required. However, there might be
some cost impacts for manufacturers of lower speed rated load range J
and L tires. Some of these tires may not meet the
[[Page 60061]]
proposed requirements in NHTSA's test program. Of the heavy-duty load
range J and L tires that did not uniformly pass the upgrade testing, we
anticipate that the costs to bring them into compliance would be no
greater than $15 per load range J tire and $95 per load range L tire.
Comments are requested on the costs of meeting the proposed changes to
571.119.
Regulatory Flexibility Act
Pursuant to the Regulatory Flexibility Act (5 U.S.C. 601 et seq.,
as amended by the Small Business Regulatory Enforcement Fairness Act
(SBREFA) of 1996), whenever an agency is required to publish a notice
of proposed rulemaking or final rule, it must prepare and make
available for public comment a regulatory flexibility analysis that
describes the effect of the rule on small entities (i.e., small
businesses, small organizations, and small governmental jurisdictions).
The Small Business Administration's regulations at 13 CFR Part 121
define a small business, in part, as a business entity ``which operates
primarily within the United States.'' (13 CFR 121.105(a)). No
regulatory flexibility analysis is required if the head of an agency
certifies the rulemaking will not have a significant economic impact on
a substantial number of small entities. SBREFA amended the Regulatory
Flexibility Act to require Federal agencies to provide a statement of
the factual basis for certifying that a rule will not have a
significant economic impact on a substantial number of small entities.
NHTSA has considered the effects of this proposed rule under the
Regulatory Flexibility Act. I certify that this proposed rule would not
have a significant economic impact on a substantial number of small
entities. The proposed rule, which would apply to new pneumatic tires,
would affect tire manufacturers and/or suppliers. The agency does not
believe that any of the tire manufacturers affected by this proposed
rule are small businesses. However, small tire retail outlets across
the country could in some small way be impacted by the proposal, in
that the cost of some tires might increase.
The agency requests comments concerning the economic impact of the
proposed rule on any small tire manufacturers, tire retail outlets, or
any other entities which the agency has not mentioned.
Executive Order 13132 (Federalism)
NHTSA has examined today's proposed rule pursuant to Executive
Order 13132 (64 FR 43255; Aug. 10, 1999) and concluded that no
additional consultation with States, local governments, or their
representatives is mandated beyond the rulemaking process. The agency
has concluded that the proposal does not have sufficient federalism
implications to warrant consultation with State and local officials or
the preparation of a federalism summary impact statement. The proposed
rule does not have ``substantial direct effects on the States, on the
relationship between the national government and the States, or on the
distribution of power and responsibilities among the various levels of
government.''
NHTSA rules can have preemptive effect in two ways. First, the
National Traffic and Motor Vehicle Safety Act contains an express
preemption provision:
When a motor vehicle safety standard is in effect under this
chapter, a State or a political subdivision of a State may prescribe
or continue in effect a standard applicable to the same aspect of
performance of a motor vehicle or motor vehicle equipment only if
the standard is identical to the standard prescribed under this
chapter.
49 U.S.C. 30103(b)(1). It is this statutory command that preempts
any non-identical State legislative and administrative law \34\
addressing the same aspect of performance, not today's rulemaking.
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\34\ The issue of potential preemption of State tort law is
addressed in the immediately following paragraph discussing implied
preemption.
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Second, the Supreme Court has recognized the possibility, in some
instances, of implied preemption of State requirements imposed on motor
vehicle manufacturers, including sanctions imposed by State tort law.
That possibility is dependent upon there being an actual conflict
between a FMVSS and the State requirement. If and when such a conflict
exists, the Supremacy Clause of the Constitution makes the State
requirements unenforceable. See Geier v. American Honda Motor Co., 529
U.S. 861 (2000), finding implied preemption of State tort law on the
basis of a conflict discerned by the court,\35\ not on the basis of an
intent to preempt asserted by the agency itself.\36\
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\35\ The conflict was discerned based upon the nature (e.g., the
language and structure of the regulatory text) and the safety-
related objectives of FMVSS requirements in question and the impact
of the State requirements on those objectives.
\36\ Indeed, in the rulemaking that established the rule at
issue in Geier, the agency did not assert preemption.
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NHTSA has considered the nature (e.g., the language and structure
of the regulatory text) and objectives of today's proposed rule and
does not discern any existing State requirements that conflict with the
proposed rule or the potential for any future State requirements that
might conflict with it. Without any conflict, there could not be any
implied preemption of State law, including State tort law.
National Technology Transfer and Advancement Act
Under the National Technology Transfer and Advancement Act of 1995
(NTTAA) (Pub. L. 104-113), ``all Federal agencies and departments shall
use technical standards that are developed or adopted by voluntary
consensus standards bodies, using such technical standards as a means
to carry out policy objectives or activities determined by the agencies
and departments.'' Voluntary consensus standards are technical
standards (e.g., materials specifications, test methods, sampling
procedures, and business practices) that are developed or adopted by
voluntary consensus standards bodies, such as the Society of Automotive
Engineers (SAE). The NTTAA directs us to provide Congress, through OMB,
explanations when we decide not to use available and applicable
voluntary consensus standards.
NHTSA was unable to find any voluntary consensus standards relevant
to this rulemaking. Additionally, please see section VI.A.1 above for
discussion of international standards considered by the agency in this
rulemaking.
Unfunded Mandates Reform Act
The Unfunded Mandates Reform Act of 1995 requires agencies to
prepare a written assessment of the costs, benefits and other effects
of proposed or final rules that include a Federal mandate likely to
result in the expenditure by State, local, or tribal governments, in
the aggregate, or by the private sector, of more than $100 million
annually (adjusted for inflation with base year of 1995). This proposed
rule will not result in expenditures by State, local, or tribal
governments, in the aggregate, or by the private sector in excess of
$100 million annually.
National Environmental Policy Act
NHTSA has analyzed this rulemaking action for the purposes of the
National Environmental Policy Act. The agency has determined that
implementation of this action will not have any significant impact on
the quality of the human environment.
Executive Order 12988
With respect to the review of the promulgation of a new regulation,
section 3(b) of Executive Order 12988, ``Civil Justice Reform'' (61 FR
4729,
[[Page 60062]]
February 7, 1996) requires that Executive agencies make every
reasonable effort to ensure that the regulation: (1) Clearly specifies
the preemptive effect; (2) clearly specifies the effect on existing
Federal law or regulation; (3) provides a clear legal standard for
affected conduct, while promoting simplification and burden reduction;
(4) clearly specifies the retroactive effect, if any; (5) adequately
defines key terms; and (6) addresses other important issues affecting
clarity and general draftsmanship under any guidelines issued by the
Attorney General. This document is consistent with that requirement.
Pursuant to this Order, NHTSA notes as follows.
The issue of preemption is discussed above in connection with E.O.
13132. NHTSA notes further that there is no requirement that
individuals submit a petition for reconsideration or pursue other
administrative proceeding before they may file suit in court.
Paperwork Reduction Act
Under the Paperwork Reduction Act of 1995 (PRA), a person is not
required to respond to a collection of information by a Federal agency
unless the collection displays a valid OMB control number. This
proposed rule contains no reporting requirements or requests for
information.
Plain Language
Executive Order 12866 and the President's memorandum of June 1,
1998, require each agency to write all rules in plain language.
Application of the principles of plain language includes consideration
of the following questions:
Have we organized the material to suit the public's needs?
Are the requirements in the rule clearly stated?
Does the rule contain technical language or jargon that
isn't clear?
Would a different format (grouping and order of sections,
use of headings, paragraphing) make the rule easier to understand?
Would more (but shorter) sections be better?
Could we improve clarity by adding tables, lists, or
diagrams?
What else could we do to make the rule easier to
understand?
If you have any responses to these questions, please include them
in your comments on this proposal.
Regulation Identifier Number (RIN)
The Department of Transportation assigns a regulation identifier
number (RIN) to each regulatory action listed in the Unified Agenda of
Federal Regulations. The Regulatory Information Service Center
publishes the Unified Agenda in April and October of each year. You may
use the RIN contained in the heading at the beginning of this document
to find this action in the Unified Agenda.
Privacy Act
Please note that anyone is able to search the electronic form of
all comments received into any of our dockets by the name of the
individual submitting the comment (or signing the comment, if submitted
on behalf of an association, business, labor union, etc.). You may
review DOT's complete Privacy Act Statement in the Federal Register
published on April 11, 2000 (Volume 65, Number 70; Pages 19477-78), or
you may visit http://www.dot.gov/privacy.html.
XI. Public Participation
How do I prepare and submit comments?
Your comments must be written and in English. To ensure that your
comments are correctly filed in the Docket, please include the docket
number of this document in your comments. Your comments must not be
more than 15 pages long.\37\ We established this limit to encourage you
to write your primary comments in a concise fashion. However, you may
attach necessary additional documents to your comments. There is no
limit on the length of the attachments.
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\37\ See 49 CFR 553.21.
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Please submit your comments by a method set forth in the ADDRESSES
section at the beginning of this document.
Please note that pursuant to the Data Quality Act, in order for
substantive data to be relied upon and used by the agency, it must meet
the information quality standards set forth in the OMB and DOT Data
Quality Act guidelines. Accordingly, we encourage you to consult the
guidelines in preparing your comments. OMB's guidelines may be accessed
at http://www.whitehouse.gov/omb/fedreg/reproducible.html.
How do I submit confidential business information?
If you wish to submit any information under a claim of
confidentiality, you should submit three copies of your complete
submission, including the information you claim to be confidential
business information, to the Chief Counsel, NHTSA, at the address given
above under FOR FURTHER INFORMATION CONTACT. When you send a comment
containing information claimed to be confidential business information,
you should include a cover letter setting forth the information
specified in our confidential business information regulation.\38\
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\38\ See 49 CFR 512.
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In addition, you should submit a copy, from which you have deleted
the claimed confidential business information, to the Docket by one of
the methods set forth above.
Will the Agency Consider Late Comments?
We will consider all comments received before the close of business
on the comment closing date indicated above under DATES. To the extent
possible, we will also consider comments received after that date.
Therefore, if interested persons believe that any new information the
agency places in the docket affects their comments, they may submit
comments after the closing date concerning how the agency should
consider that information for the final rule.
If a comment is received too late for us to consider in developing
a final rule (assuming that one is issued), we will consider that
comment as an informal suggestion for future rulemaking action.
How Can I Read the Comments Submitted By Other People?
You may read the materials placed in the docket for this document
(e.g., the comments submitted in response to this document by other
interested persons) at any time by going to http://www.regulations.gov.
Follow the online instructions for accessing the dockets. You may also
read the materials at the DOT Docket .
List of Subjects in 49 CFR Part 571
Imports, Motor vehicle safety, Motor vehicles, Rubber and rubber
products, and Tires.
In consideration of the foregoing, we propose to amend 49 CFR part
571 to read as follows:
PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS
1. The authority citation for Part 571 continues to read as
follows:
Authority: 49 U.S.C. 322, 30111, 30115, 30166 and 30177;
delegation of authority at 49 CFR 1.50.
2. Section 571.119 is amended by revising S3(a), S6.1.2(b), S6.3,
S6.5(e), S7.1.2, S7.2(a), S7.2(e), S7.4, S7.4.1, S7.4.2, and Table III,
by removing and reserving S3(b), and by adding definitions to S4, in
alphabetical order.
[[Page 60063]]
The revised and added paragraphs read as follows:
Sec. 571.119 Standard No. 119; New pneumatic tires for motor vehicles
with a GVWR of more than 4,536 kilograms (10,000 pounds) and
motorcycles.
* * * * *
S3. * * *
(a) New pneumatic light truck tires, for use on motor vehicles with
a GVWR of 4,536 kilograms (10,000 pounds) or less manufactured after
1948, of the following type: With a tread depth of 18/32 inch or
greater, bias-ply with tread depth of 18/32 inch or less, and speed-
restricted service.
(b) [Reserved]
* * * * *
S4. * * *
Bias ply tire means a pneumatic tire in which the ply cords that
extend to the beads are laid at alternate angles substantially less
than 90 degrees to the centerline of the tread.
* * * * *
Maximum speed rating means the maximum speed, as specified by the
tire manufacturer, at which the tire can carry a load corresponding to
the maximum load rating for single usage at the corresponding inflation
pressure.
* * * * *
Non-speed-restricted service tire means a tire with a maximum speed
rating above 90 km/h (55 mph).
Radial ply tire means a pneumatic tire in which the ply cords that
extend to the beads are laid at substantially 90 degrees to the
centerline of the tread.
Speed-restricted service tire means a tire with a maximum speed
rating of 90 km/h (55 mph) or less.
* * * * *
S6.1.2 * * *
(b) The tire pressure, when measured at any time between 15 minutes
and 25 minutes after the end of the test, shall not be less than 95
percent of the initial pressure specified in S7.2(a), for the endurance
test, and in S7.4.2(a) for the high speed test.
* * * * *
S6.3 High-speed performance. When tested in accordance with the
procedures of S7.4, a tire shall meet the requirements set forth in
S6.1.1 and S6.1.2(a) and (b). However, this requirement applies only to
motorcycle tires, to non-speed restricted tires of nominal rim diameter
code 14.5 or less marked load range A, B, C, or D, and to non-speed
restricted radial tires marked load range F, G, H, J, or L.
* * * * *
S6.5 * * *
(e)(1) Subject to S6.5(e)(2), the speed that corresponds to the
maximum speed rating for each speed-restricted service tire and each
non-speed-restricted service radial tire of load range F, G, H, J, and
L shall be shown as follows:
Max speed ------ km/h (------ mph)
(2) For each non-speed-restricted service radial tire of load range
F, G, H, J, and L, the speed shown shall be in a multiple of 10 km/h.
* * * * *
S7.1.2 The tire must be capable of meeting the requirements of S7.2
and S7.4 when conditioned to a temperature of 35 [deg]C 3
[deg]C (95 [deg]F 5 [deg]F) for 3 hours before the test is
conducted, and with an ambient temperature maintained at 35 [deg]C
3 [deg]C (95 [deg]F 5 [deg]F) during all
phases of testing. The tire must be capable of meeting the requirements
of S7.3 when conditioned at a temperature of 21 [deg]C 3
[deg]C (70 [deg]F 5 [deg]F) for 3 hours before the test is
conducted.
S7.2 Endurance. (a) Mount the tire on a model rim assembly and
inflate it as follows: For a non-speed restricted radial tire of load
range F, G, H, J, or L, inflate it to 80 percent of the inflation
pressure corresponding to the maximum load rating marked on the tire.
For all other tires, inflate it to 100 percent of the inflation
pressure corresponding to the maximum load rating marked on the tire.
Use the single maximum load value when the tire is marked with both
single and dual maximum loads.
* * * * *
(e) Allow the tire to cool for between 15 and 25 minutes after
running the tire for the required time. Measure the tire inflation
pressure. Remove the tire from the model rim assembly, and inspect the
tire for conditions specified in S6.1.2(a) and (b).
* * * * *
S7.4 High-speed performance.
S7.4.1 Motorcycle tires, and non-speed restricted tires of nominal
rim diameter code 14.5 or less marked load range A, B, C, or D.
(a) Mount the tire on a test rim and inflate it to the pressure
corresponding to the maximum load rating marked on the tire. Use the
single maximum load value when the tire is marked with both single and
dual maximum load.
(b) Condition the tire and rim assembly in accordance with S7.1.2.
(c) Before or after mounting the assembly on a test axle, adjust
the tire pressure to that specified in S7.4.1(a).
(d) Mount the tire-rim assembly on an axle and press it against a
flat-faced steel test wheel that is 1708 mm (67.23 inches) in diameter
and at least as wide as the tread of the tire
(e) Apply a force of 88 percent of the maximum load rating marked
on the tire (use the single maximum load value when the tire is marked
with both single and dual maximum loads), and conduct the break-in
procedure at 80 km/h (50 mph) for 2 hours.
(f) Remove the load, allow the tire to cool to 35 [deg]C 3 [deg]C (95 [deg]F 5 [deg]F), and then adjust the
pressure to that specified in S7.4.1(a).
(g) Reapply the same load, and without interruption or readjustment
of inflation pressure, conduct the test at 120 km/h (75 mph) for 30
minutes, then at 129 km/h (80 mph) for 30 minutes, and then at 137 km/h
(85 mph) for 30 minutes.
(h) Allow the tire to cool between 15 minutes and 25 minutes.
Measure its inflation pressure. Then, deflate the tire, remove the tire
from the test rim, and inspect the tire for conditions specified in
S6.1.2 (a) and (b).
S7.4.2 Non-speed restricted radial tires marked load range F, G, H,
J, or L.
(a) Mount the tire on a test rim and inflate it to the pressure
corresponding to 90 percent of the maximum load rating marked on the
tire. Use a single maximum value when the tire is marked with both
single and dual maximum load.
(b) Condition the tire in accordance with S7.1.2.
(c) Before or after mounting the assembly on a test axle, adjust
the tire pressure to that specified in S7.4.2(a).
(d) Mount the tire-rim assembly on an axle and press it against a
flat-faced steel test wheel that is 1708 mm (67.23 inches) in diameter
and at least as wide as the tread of the tire.
(e) Apply a force of 85 percent of the maximum load rating marked
on the tire (use the single maximum load value when the tire is marked
with both single and dual maximum loads), and conduct the break-in
procedure at 80 km/h (50 mph) for 2 hours.
(f) Remove the load, allow the tire to cool to 35 [deg]C 3 [deg]C (95 [deg]F 5 [deg]F), and then adjust the
pressure to S7.4.2(a).
(g) Reapply the same load, and without interruption or readjustment
of inflation pressure, conduct the test at maximum speed rating less 20
km/h for 30 minutes, then at maximum speed rating less 10 km/h for 30
minutes, and then at maximum speed rating for 30 minutes.
(h) Allow the tire to cool for between 15 minutes and 25 minutes.
Measure its inflation pressure. Then, deflate the tire, remove the tire
from the test rim, and inspect the tire for conditions specified in
S6.1.2(a) and (b).
* * * * *
[[Page 60064]]
Table III--Endurance Test Schedule
----------------------------------------------------------------------------------------------------------------
Test wheel Test load: Percent of maximum load
speed rating
Description Load range ---------------------------------------------------
II--16 III--24
km/h I--7 hours hours hours
----------------------------------------------------------------------------------------------------------------
Speed-restricted service:
90 km/h (55 mph)........... All........................ 40 66 84 101
80 km/h (50 mph)........... C, D....................... 48 75 97 114
E, F, G, H, J, L, M, N..... 32 66 84 101
56 km/h (35 mph)........... All........................ 24 66 84 101
Motorcycle..................... All........................ 80 \1\ 100 \2\ 108 117
Radial......................... F, G, H, J, L.............. 80 85 90 100
All other...................... A, B, C, D................. 80 \1\ 75 \2\ 97 114
E.......................... 64 70 88 106
F.......................... 64 66 84 101
G.......................... 56 66 84 101
H, J, L, M, N.............. 48 66 84 101
----------------------------------------------------------------------------------------------------------------
\1\ 4 hours for tire sizes subject to high speed requirements S6.3 .
\2\ 6 hours for tire sizes subject to high speed requirements S6.3.
Issued: September 23, 2010.
Joseph Carra,
Acting Associate Administrator for Rulemaking.
[FR Doc. 2010-24347 Filed 9-28-10; 8:45 am]
BILLING CODE 4910-59-P