[Code of Federal Regulations]
[Title 40, Volume 16]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR86.004-28]

[Page 52-56]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 86--CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES--Table of Contents
 
  Subpart A--General Provisions for Emission Regulations for 1977 and 
 
Sec. 86.004-28  Compliance with emission standards.

    Section 86.004-28 includes text that specifies requirements that 
differ from Sec. 86.094-28, Sec. 86.098-28, Sec. 86.000-28 or 
Sec. 86.001-28. Where a paragraph in Sec. 86.094-28, Sec. 86.098-28, 
Sec. 86.000-28 or Sec. 86.001-28 is identical and applicable to 
Sec. 86.004-28, this may be indicated by specifying the corresponding 
paragraph and the statement ``[Reserved]. For guidance see Sec. 86.094-
28.'' or ``[Reserved]. For guidance see Sec. 86.098-28.'' or 
``[Reserved]. For guidance see Sec. 86.000-28.'' or ``[Reserved]. For 
guidance see Sec. 86.001-28.''

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    (a)(1) through (a)(2) [Reserved. For guidance see Sec. 86.000-28.
    (a)(3) [Reserved]. For guidance see Sec. 86.094-28.
    (a)(4) introductory text [Reserved]. For guidance see Sec. 86.098-
28.
    (a)(4)(i) [Reserved]. For guidance see Sec. 86.000-28.
    (a)(4)(i)(A) through (a)(4)(i)(B)(2)(i) [Reserved. For guidance see 
Sec. 86.094-28.
    (a)(4)(i)(B)(2)(ii) [Reserved]. For guidance see Sec. 86.000-28.
    (a)(4)(i)(B)(2)(iii) through (a)(4)(i)(B)(2)(iv) [Reserved]. For 
guidance see Sec. 86.094-28.
    (a)(4)(i)(C) through (a)(4)(i)(D)(2) [Reserved]. For guidance see 
Sec. 86.098-28.
    (a)(4)(ii)(A)(1) through (a)(4)(ii)(A)(2) [Reserved]. For guidance 
see Sec. 86.000-28.
    (a)(4)(ii)(B) through (a)(4)(ii)(C) [Reserved]. For guidance see 
Sec. 86.098-28.
    (a)(4)(iii) [Reserved]. For guidance see Sec. 86.000-28.
    (a)(4)(iv) [Reserved]. For guidance see Sec. 86.094-28.
    (a)(4)(v) [Reserved]. For guidance see Sec. 86.098-28.
    (a)(5) through (a)(6) [Reserved]. For guidance see Sec. 86.094-28.
    (a)(7) introductory text [Reserved]. For guidance see Sec. 86.098-
28.
    (a)(7)(i) [Reserved]. For guidance see Sec. 86.000-28.
    (a)(7)(ii) [Reserved]. For guidance see Sec. 86.094-28.
    (b)(1) This paragraph (b) applies to light-duty trucks.
    (2) Each exhaust, evaporative and refueling emission standard (and 
family emission limits, as appropriate) of Sec. 86.004-9 applies to the 
emissions of vehicles for the appropriate useful life as defined in 
Secs. 86.098-2 and 86.004-9.
    (b)(3) through (b)(4)(i) [Reserved]. For guidance see Sec. 86.094-
28.
    (b)(4)(ii) through (b)(6) [Reserved]. For guidance see Sec. 86.000-
28.
    (b)(7)(i) through (b)(9) [Reserved]. For guidance see Sec. 86.001-
28.
    (c)(1) Paragraph (c) of this section applies to heavy-duty engines.
    (2) The applicable exhaust emission standards (or family emission 
limits, as appropriate) for Otto-cycle engines and for diesel-cycle 
engines apply to the emissions of engines for their useful life.
    (3) Since emission control efficiency generally decreases with the 
accumulation of service on the engine, deterioration factors will be 
used in combination with emission data engine test results as the basis 
for determining compliance with the standards.
    (4)(i) Paragraph (c)(4) of this section describes the procedure for 
determining compliance of an engine with emission standards (or family 
emission limits, as appropriate), based on deterioration factors 
supplied by the manufacturer. Deterioration factors shall be established 
using applicable emissions test procedures. NOX plus NMHC 
deterioration factors shall be established based on the sum of the 
pollutants. When establishing deterioration factors for NOX 
plus NMHC, a negative deterioration (emissions decrease from the 
official exhaust emissions test result) for one pollutant may not offset 
deterioration of the other pollutant. Where negative deterioration 
occurs for NOX and/or NMHC, the official exhaust emission 
test result shall be used for purposes of determining the NOX 
plus NMHC deterioration factor.
    (ii) Separate exhaust emission deterioration factors, determined 
from tests of engines, subsystems, or components conducted by the 
manufacturer, shall be supplied for each engine-system combination. For 
Otto-cycle engines, separate factors shall be established for transient 
NMHC (NMHCE), CO, NOX, NOX plus NMHC, and idle CO, 
for those engines utilizing aftertreatment technology (e.g., catalytic 
converters). For diesel-cycle engines, separate factors shall be 
established for transient NMHC (NMHCE), CO, NOX, 
NOX plus NMHC and exhaust particulate. For diesel-cycle smoke 
testing, separate factors shall also be established for the acceleration 
mode (designated as ``A''), the lugging mode (designated as ``B''), and 
peak opacity (designated as ``C'').
    (iii)(A) Paragraphs (c)(4)(iii)(A) (1) and (2) of this section apply 
to Otto-cycle HDEs.
    (1) Otto-cycle HDEs not utilizing aftertreatment technology (e.g., 
catalytic converters). For transient NMHC (NMHCE), CO, NOX, 
the official exhaust emission results for each emission data engine at 
the selected test point shall

[[Page 54]]

be adjusted by the addition of the appropriate deterioration factor. 
However, if the deterioration factor supplied by the manufacturer is 
less than zero, it shall be zero for the purposes of this paragraph.
    (2) Otto-cycle HDEs utilizing aftertreatment technology (e.g., 
catalytic converters). For transient NMHC (NMHCE), CO, NOX, 
and for idle CO, the official exhaust emission results for each emission 
data engine at the selected test point shall be adjusted by 
multiplication by the appropriate deterioration factor, except as 
otherwise provided in paragraph (c)(4)(iii)(A)(3) of this section. The 
deterioration factor must be calculated by dividing the exhaust 
emissions at full useful life by the stabilized mileage emission level 
(reference Sec. 86.096-26(c)(4), e.g., 125 hours). However, if the 
deterioration factor supplied by the manufacturer is less than one, it 
shall be one for purposes of this paragraph (c)(4)(iii)(A)(2).
    (3) An Otto-cycle heavy-duty engine manufacturer who believes that a 
deterioration factor derived using the calculation methodology described 
in paragraph (c)(4)(iii)(4)(A)(2) of this section are significantly 
unrepresentative for one or more engine families (either too high or too 
low) may petition the Administrator to allow for the use of an additive 
rather than a multiplicative deterioration factor. This petition must 
include full rationale behind the request together with any supporting 
data or other evidence. Based on this or other information the 
Administration may allow for an alternative procedure. Any petition 
should be submitted in a timely manner, to allow adequate time for a 
thorough evaluation. Manufacturers using an additive deterioration 
factor under this paragraph (c)(4)(iii)(A)(3) must perform in-use 
verification testing to determine if the additive deterioration factor 
reasonably predicts actual in-use emissions. The plan for the in-use 
verification testing must be approved by the Administrator as part of 
the approval process described in this paragraph (c)(4)(iii)(4)(A)(3) 
prior to the use of the additive deterioration factor. The Administrator 
may consider the results of the in-use verification testing both in 
certification and in-use compliance programs.
    (B) Paragraph (c)(4)(iii)(B) of this section applies to diesel-cycle 
HDEs.
    (1) Diesel-cycle HDEs not utilizing aftertreatment technology (e.g., 
particulate traps). For transient NMHC (NMHCE), CO, NOX, 
NOX plus NMHC, and exhaust particulate, the official exhaust 
emission results for each emission data engine at the selected test 
point shall be adjusted by the addition of the appropriate deterioration 
factor. However, if the deterioration factor supplied by the 
manufacturer is less than zero, it shall be zero for the purposes of 
this paragraph.
    (2) Diesel-cycle HDEs utilizing aftertreatment technology (e.g., 
particulate traps). For transient NMHC (NMHCE), CO, NOX, 
NOX plus NMHC, and exhaust particulate, the official exhaust 
emission results for each emission data engine at the selected test 
point shall be adjusted by multiplication by the appropriate 
deterioration factor. However, if the deterioration factor supplied by 
the manufacturer is less than one, it shall be one for the purposes of 
this paragraph.
    (3) Diesel-cycle HDEs only. For acceleration smoke (``A''), lugging 
smoke (``B''), and peak smoke (``C''), the official exhaust emission 
results for each emission data engine at the selected test point shall 
be adjusted by the addition of the appropriate deterioration factor. 
However, if the deterioration factor supplied by the manufacturer is 
less than zero, it shall be zero for the purposes of this paragraph.
    (iv) The emission values to compare with the standards (or family 
emission limits, as appropriate) shall be the adjusted emission values 
of paragraph (c)(4)(iii) of this section, rounded to the same number of 
significant figures as contained in the applicable standard in 
accordance with ASTM E 29-93a (as referenced in Sec. 86.094-28 
(a)(4)(i)(B)(2)(ii)), for each emission data engine.
    (5) and (6) [Reserved]
    (7) Every test engine of an engine family must comply with all 
applicable standards (or family emission limits, as appropriate), as 
determined in paragraph (c)(4)(iv) of this section, before any engine in 
that family will be certified.

[[Page 55]]

    (8) For the purposes of setting an NMHC plus NOx 
certification level or FEL for a diesel-fueled engine family, the 
manufacturer may use one of the following options for the determination 
of NMHC for an engine family. The manufacturer must declare which option 
is used in its application for certification of that engine family.
    (i) THC may be used in lieu of NMHC for the standards set forth in 
Sec. 86.004-11.
    (ii) The manufacturer may choose its own method to analyze methane 
with prior approval of the Administrator.
    (iii) The manufacturer may assume that two percent of the measured 
THC is methane (NMHC =0.98 x THC).
    (d)(1) Paragraph (d) of this section applies to heavy-duty vehicles 
equipped with gasoline-fueled or methanol-fueled engines.
    (2) The applicable evaporative emission standards in this subpart 
apply to the emissions of vehicles for their useful life.
    (3)(i) For vehicles with a GVWR of up to 26,000 pounds, because it 
is expected that emission control efficiency will change during the 
useful life of the vehicle, an evaporative emission deterioration factor 
shall be determined from the testing described in Sec. 86.098-23(b)(3) 
for each evaporative emission family-evaporative emission control system 
combination to indicate the evaporative emission control system 
deterioration during the useful life of the vehicle (minimum 50,000 
miles). The factor shall be established to a minimum of two places to 
the right of the decimal.
    (ii) For vehicles with a GVWR of greater than 26,000 pounds, because 
it is expected that emission control efficiency will change during the 
useful life of the vehicle, each manufacturer's statement as required in 
Sec. 86.098-23(b)(4)(ii) shall include, in accordance with good 
engineering practice, consideration of control system deterioration.
    (4) The evaporative emission test results, if any, shall be adjusted 
by the addition of the appropriate deterioration factor, provided that 
if the deterioration factor as computed in paragraph (d)(3) of this 
section is less than zero, that deterioration factor shall be zero for 
the purposes of this paragraph.
    (5) The emission level to compare with the standard shall be the 
adjusted emission level of paragraph (d)(4) of this section. Before any 
emission value is compared with the standard, it shall be rounded, in 
accordance with ASTM E 29-93a (as referenced in Sec. 86.094-28 
(a)(4)(i)(B)(2)(ii)), to two significant figures. The rounded emission 
values may not exceed the standard.
    (6) Every test vehicle of an evaporative emission family must comply 
with the evaporative emission standard, as determined in paragraph 
(d)(5) of this section, before any vehicle in that family may be 
certified.
    (e) [Reserved]
    (f) through (g)(3) [Reserved]. For guidance see Sec. 86.001-28.
    (g)(4) Vehicles certified to the refueling emission standard under 
this provision shall not be counted in the sales percentage compliance 
determinations for the 2004, 2005 and subsequent model years.
    (h) [Reserved]. For guidance see Sec. 86.001-28.
    (i) Emission results from heavy-duty engines equipped with exhaust 
aftertreatment may need to be adjusted to account for regeneration 
events. This provision only applies for engines equipped with emission 
controls that are regenerated on an infrequent basis. For the purpose of 
this paragraph (i), the term ``regeneration'' means an event during 
which emissions levels change while the aftertreatment performance is 
being restored by design. Examples of regenerations are increasing 
exhaust gas temperature to remove sulfur from an adsorber or increasing 
exhaust gas temperature to oxidize PM in a trap. For the purpose of this 
paragraph (i), the term ``infrequent'' means having an expected 
frequency of less than once per transient test cycle. Calculation and 
use of adjustment factors are described in paragraphs (i)(1) through 
(i)(5) of this section.
    (1) Development of adjustment factors. Manufacturers must develop 
separate pairs of adjustment factors (an upward adjustment factor and a 
downward adjustment factor) for each pollutant based on measured 
emission data and observed regeneration frequency. Adjustment factors 
may be carried-over

[[Page 56]]

to subsequent model years or carried-across to other engine families 
only where the Administrator determines that such carry-over or carry-
across is consistent with good engineering judgment. Adjustment factors 
should generally apply to an entire engine family, but manufacturers may 
develop separate adjustment factors for different engine configurations 
within an engine family. All adjustment factors for regeneration are 
additive.
    (2) Calculation of adjustment factors. The adjustment factors are 
calculated from the following parameters: the measured emissions from a 
test in which the regeneration occurs (EFH), the measured 
emissions from a test in which the regeneration does not occur 
(EFL), and the frequency of the regeneration event in terms 
of fraction of tests during which the regeneration occurs (F). The 
average emission rate (EFA) is calculated as:

EFA = (F)(EFH) + (1 - F)(EFL)

    (i) The upward adjustment factor (UAF) is calculated as: UAF = 
EFA - EFL.
    (ii) The downward adjustment factor (DAF) is calculated as: DAF = 
EFA - EFH.
    (3) Use of adjustment factors. Upward adjustment factors are added 
to measured emission rates for all tests in which the regeneration does 
not occur. Downward adjustment factors are added to measured emission 
rates for all tests in which the regeneration occurs. The occurrence of 
the regeneration must be identified in a manner that is readily apparent 
during all testing. Where no regeneration is identified, the upward 
adjustment factor shall be applied.
    (4) Sample calculation. If EFL is 0.10 g/bhp-hr, 
EFH is 0.50 g/bhp-hr, and F is 0.1 (i.e., the regeneration 
occurs once for each ten tests), then:

EFA = (0.1)(0.5 g/bhp-hr) + (1.0 - 0.1)(0.1 g/bhp-hr) = 0.14 
    g/bhp-hr
UAF = 0.14 g/bhp-hr - 0.10 g/bhp-hr = 0.04 g/bhp-hr
DAF = 0.14 g/bhp-hr - 0.50 g/bhp-hr = -0.36 g/bhp-hr

    (5) Options. (i) A manufacturer may elect to omit adjustment factors 
for one or more of its engine families (or configurations) because the 
effect of the regeneration is small, or because it is not practical to 
identify when regenerations occur. In these cases, no upward or downward 
adjustment factor shall be added, and the manufacturer is liable for 
compliance with the emission standards for all tests, without regard to 
whether a regeneration occurs.
    (ii) Upon request by the manufacturer, the Administrator may account 
for regeneration events differently than is provided in this paragraph 
(i). However, this option only applies for events that occur extremely 
infrequently, and which cannot be practically addressed using the 
adjustment factors described in this paragraph (i).

[61 FR 54890, Oct. 22, 1996, as amended at 62 FR 54726, Oct. 21, 1997; 
65 FR 59948, Oct. 6, 2000; 66 FR 5159, Jan. 18, 2001]