[Code of Federal Regulations]
[Title 40, Volume 29]
[Revised as of July 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR600.113-08]
[Page 893-898]
TITLE 40--PROTECTION OF ENVIRONMENT
CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
PART 600_FUEL ECONOMY OF MOTOR VEHICLES--Table of Contents
Subpart B_Fuel Economy Regulations for 1978 and Later Model Year
Automobiles_Test Procedures
Sec. 600.113-08 Fuel economy calculations for FTP, HFET, US06, SC03 and cold temperature FTP tests.
The Administrator will use the calculation procedure set forth in
this paragraph for all official EPA testing of vehicles fueled with
gasoline, diesel, alcohol-based or natural gas fuel. The calculations of
the weighted fuel economy values require input of the weighted grams/
mile values for total hydrocarbons (HC), carbon monoxide (CO), and
carbon dioxide (CO2); and, additionally for methanol-fueled
automobiles, methanol (CH3OH) and formaldehyde (HCHO); and
additionally for natural gas-fueled vehicles non-methane hydrocarbons
(NMHC) and methane (CH4) for the FTP, HFET, US06, SC03 and
cold temperature FTP tests. Additionally, the specific gravity, carbon
weight fraction and net heating value of the test fuel must be
determined. The FTP, HFET, US06, SC03 and cold temperature FTP fuel
economy values shall be calculated as specified in this section. An
example appears in Appendix II of this part.
(a) Calculate the FTP fuel economy.
(1) Calculate the weighted grams/mile values for the FTP test for
HC, CO and CO2; and, additionally for methanol-fueled
automobiles, CH3OH and HCHO; and additionally for natural
gas-fueled automobiles NMHC and CH4 as specified in Sec.
86.144 of this chapter. Measure and record the test fuel's properties as
specified in paragraph (f) of this section.
(2) Calculate separately the grams/mile values for the cold
transient phase, stabilized phase and hot transient phase of the FTP
test. For vehicles with more than one source of propulsion energy, one
of which is a rechargeable energy storage system, or vehicles with
special features that the Administrator determines may have a
rechargeable energy source, whose charge can vary during the test,
calculate separately the grams/mile values for the cold transient phase,
stabilized phase, hot transient phase and hot stabilized phase of the
FTP test.
(b) Calculate the HFET fuel economy.
(1) Calculate the mass values for the highway fuel economy test for
HC, CO and CO2, and where applicable CH3OH, HCHO,
NMHC and CH4 as specified in Sec. 86.144(b) of this chapter.
Measure and record the test fuel's properties as specified in paragraph
(f) of this section.
(2) Calculate the grams/mile values for the highway fuel economy
test for HC, CO and CO2, and where applicable
CH3OH, HCHO, NMHC and CH4 by dividing the mass
values obtained in paragraph (b)(1) of this section, by the actual
distance traveled, measured in miles, as specified in Sec. 86.135(h) of
this chapter.
(c) Calculate the cold temperature FTP fuel economy.
(1) Calculate the weighted grams/mile values for the cold
temperature FTP test for HC, CO and CO2; and, additionally
for methanol-fueled automobiles, CH3OH and HCHO; and
additionally for natural gas-fueled automobiles NMHC and CH4
as specified in Sec. 86.244 of this chapter. For 2008 through 2010
diesel-fueled vehicles, HC measurement is optional.
(2) Calculate separately the grams/mile values for the cold
transient phase, stabilized phase and hot transient phase of the cold
temperature FTP test in Sec. 86.244 of this chapter.
[[Page 894]]
(3) Measure and record the test fuel's properties as specified in
paragraph (f) of this section.
(d) Calculate the US06 fuel economy.
(1) Calculate the total grams/mile values for the US06 test for HC,
CO and CO2; and where applicable CH3OH, HCHO, NMHC
and CH4, as specified in Sec. 86.164 of this chapter.
(2) Calculate separately the grams/mile values for HC, CO and
CO2; and where applicable CH3OH, HCHO, NMHC and
CH4, for both the US06 City phase and the US06 Highway phase
of the US06 test as specified in Sec. 86.164 of this chapter. In lieu
of directly measuring the emissions of the separate city and highway
phases of the US06 test according to the provisions of Sec. 86.159 of
this chapter, the manufacturer may, with the advance approval of the
Administrator and using good engineering judgment, optionally
analytically determine the grams/mile values for the city and highway
phases of the US06 test. To analytically determine US06 City and US06
Highway phase emission results, the manufacturer shall multiply the US06
total grams/mile values determined in paragraph (d)(1) of this section
by the estimated proportion of fuel use for the city and highway phases
relative to the total US06 fuel use. The manufacturer may estimate the
proportion of fuel use for the US06 City and US06 Highway phases by
using modal HC, CO, and CO2 emissions data, or by using
appropriate OBD data (e.g., fuel flow rate in grams of fuel per second),
or another method approved by the Administrator.
(3) Measure and record the test fuel's properties as specified in
paragraph (f) of this section.
(e) Calculate the grams/mile values for the SC03 test for HC, CO and
CO2; and additionally for methanol-fueled automobiles,
CH3OH and HCHO; and additionally for natural gas-fueled
automobiles NMHC and CH4 as specified in Sec. 86.144 of this
chapter. Measure and record the test fuel's properties as specified in
paragraph (f) of this section.
(f)(1) Gasoline test fuel properties shall be determined by analysis
of a fuel sample taken from the fuel supply. A sample shall be taken
after each addition of fresh fuel to the fuel supply. Additionally, the
fuel shall be resampled once a month to account for any fuel property
changes during storage. Less frequent resampling may be permitted if EPA
concludes, on the basis of manufacturer-supplied data, that the
properties of test fuel in the manufacturer's storage facility will
remain stable for a period longer than one month. The fuel samples shall
be analyzed to determine the following fuel properties:
(i) Specific gravity per ASTM D 1298-85 (Reapproved 1990) ``Standard
Practice for Density, Relative Density (Specific Gravity), or API
Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer
Method''. This incorporation by reference was approved by the Director
of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR
part 51. Copies may be obtained from the American Society for Testing
and Materials, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken,
PA 19428-2959. Copies may be inspected at U.S. EPA Headquarters Library,
EPA West Building, Constitution Avenue and 14th Street, NW., Room 3340,
Washington, DC, or at the National Archives and Records Administration
(NARA). For information on the availability of this material at NARA,
call 202-741-6030, or go to: http://www.archives.gov/federal--register/
code--of--federal--regulations/ibr--locations.html.
(ii) Carbon weight fraction per ASTM D 3343-90 ``Standard Test
Method for Estimation of Hydrogen Content of Aviation Fuels.'' This
incorporation by reference was approved by the Director of the Federal
Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies
may be obtained from the American Society for Testing and Materials, 100
Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959.
Copies may be inspected at U.S. EPA Headquarters Library, EPA West
Building, Constitution Avenue and 14th Street, NW., Room 3340,
Washington, DC, or at the National Archives and Records Administration
(NARA). For information on the availability of this material at NARA,
call 202-741-6030, or go to: http://www.archives.gov/federal--register/
[[Page 895]]
code--of--federal--regulations/ibr--locations.html.
(iii) Net heating value (Btu/lb) per ASTM D 3338-92 ``Standard Test
Method for Estimation of Net Heat of Combustion of Aviation Fuels.''
This incorporation by reference was approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.
Copies may be obtained from the American Society for Testing and
Materials, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA
19428-2959. Copies may be inspected at U.S. EPA Headquarters Library,
EPA West Building, Constitution Avenue and 14th Street, NW., Room 3340,
Washington, DC, or at the National Archives and Records Administration
(NARA). For information on the availability of this material at NARA,
call 202-741-6030, or go to: http://www.archives.gov/federal--register/
code--of--federal--regulations/ibr--locations.html.
(2) Methanol test fuel shall be analyzed to determine the following
fuel properties:
(i) Specific gravity using either:
(A) ASTM D 1298-85 (Reapproved 1990) ``Standard Practice for
Density, Relative Density (Specific Gravity), or API Gravity of Crude
Petroleum and Liquid Petroleum Products by Hydrometer Method'' for the
blend. This incorporation by reference was approved by the Director of
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part
51. Copies may be obtained from the American Society for Testing and
Materials, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA
19428-2959. Copies may be inspected at U.S. EPA Headquarters Library,
EPA West Building, Constitution Avenue and 14th Street, NW., Room 3340,
Washington, DC, or at the National Archives and Records Administration
(NARA). For information on the availability of this material at NARA,
call 202-741-6030, or go to: http://www.archives.gov/federal--register/
code--of--federal--regulations/ibr--locations.html or:
(B) ASTM D 1298-85 (Reapproved 1990) ``Standard Practice for
Density, Relative Density (Specific Gravity), or API Gravity of Crude
Petroleum and Liquid Petroleum Products by Hydrometer Method'' for the
gasoline fuel component and also for the methanol fuel component and
combining as follows. This incorporation by reference was approved by
the Director of the Federal Register in accordance with 5 U.S.C. 552(a)
and 1 CFR part 51. Copies may be obtained from the American Society for
Testing and Materials, 100 Barr Harbor Drive, P.O. Box C700, West
Conshohocken, PA 19428-2959. Copies may be inspected at U.S. EPA
Headquarters Library, EPA West Building, Constitution Avenue and 14th
Street, NW., Room 3340, Washington, DC, or at the National Archives and
Records Administration (NARA). For information on the availability of
this material at NARA, call 202-741-6030, or go to: http://
www.archives.gov/federal--register/code--of--federal--regulations/ibr--
locations.html.
SG = SGg x volume fraction gasoline + SGm x
volume fraction methanol.
(ii)(A) Carbon weight fraction using the following equation:
CWF = CWFg x MFg + 0.375 x MFm
Where:
CWFg = Carbon weight fraction of gasoline portion of blend
per ASTM D 3343-90 ``Standard Test Method for Estimation of
Hydrogen Content of Aviation Fuels.'' This incorporation by
reference was approved by the Director of the Federal Register
in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies
may be obtained from the American Society for Testing and
Materials, 100 Barr Harbor Drive, P.O. Box C700, West
Conshohocken, PA 19428-2959. Copies may be inspected at U.S.
EPA Headquarters Library, EPA West Building, Constitution
Avenue and 14th Street, NW., Room 3340, Washington, DC, or at
the National Archives and Records Administration (NARA). For
information on the availability of this material at NARA, call
202-741-6030, or go to: http://www.archives.gov/federal--
register/code--of--federal--regulations/ibr--locations.html.
MFg=Mass fraction gasoline=(G x SGg)/(G x
SGg + M x SGm)
MFm=Mass fraction methanol=(M x SGm)/(G x
SGg + M x SGm)
Where:
G=Volume fraction gasoline.
M=Volume fraction methanol.
SGg=Specific gravity of gasoline as measured by ASTM D 1298-
85 (Reapproved 1990)
[[Page 896]]
``Standard Practice for Density, Relative Density (Specific
Gravity), or API Gravity of Crude Petroleum and Liquid
Petroleum Products by Hydrometer Method.'' This incorporation
by reference was approved by the Director of the Federal
Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.
Copies may be obtained from the American Society for Testing
and Materials, 100 Barr Harbor Drive, P.O. Box C700, West
Conshohocken, PA 19428-2959. Copies may be inspected at U.S.
EPA Headquarters Library, EPA West Building, Constitution
Avenue and 14th Street, NW, Room 3340, Washington DC, or at
the National Archives and Records Administration (NARA). For
information on the availability of this material at NARA, call
202-741-6030, or go to: http://www.archives.gov/federal--
register/code--of--federal--regulations/ibr--locations.html.
SGm=Specific gravity of methanol as measured by ASTM D 1298-
85 (Reapproved 1990) ``Standard Practice for Density, Relative
Density (Specific Gravity), or API Gravity of Crude Petroleum
and Liquid Petroleum Products by Hydrometer Method.'' This
incorporation by reference was approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR
part 51. Copies may be obtained from the American Society for
Testing and Materials, 100 Barr Harbor Drive, P.O. Box C700,
West Conshohocken, PA 19428-2959. Copies may be inspected at
U.S. EPA Headquarters Library, EPA West Building, Constitution
Avenue and 14th Street, NW, Room 3340, Washington DC, or at
the National Archives and Records Administration (NARA). For
information on the availability of this material at NARA, call
202-741-6030, or go to: http://www.archives.gov/federal--
register/code--of--federal--regulations/ibr--locations.html.
(B) Upon the approval of the Administrator, other procedures to
measure the carbon weight fraction of the fuel blend may be used if the
manufacturer can show that the procedures are superior to or equally as
accurate as those specified in this paragraph (f)(2)(ii).
(iii) Net heating value (BTU/lb) per ASTM D 240-92 ``Standard Test
Method for Heat of Combustion of Liquid Hydrocarbon Fuels by Bomb
Calorimeter.'' This incorporation by reference was approved by the
Director of the Federal Register in accordance with 5 U.S.C. 552(a) and
1 CFR part 51. Copies may be obtained from the American Society for
Testing and Materials, 100 Barr Harbor Drive, P.O. Box C700, West
Conshohocken, PA 19428-2959. Copies may be inspected at U.S. EPA
Headquarters Library, EPA West Building, Constitution Avenue and 14th
Street, NW, Room 3340, Washington DC, or at the National Archives and
Records Administration (NARA). For information on the availability of
this material at NARA, call 202-741-6030, or go to: http://
www.archives.gov/federal--register/code--of--federal--regulations/ibr--
locations.html.
(3) Natural gas test fuel shall be analyzed to determine the
following fuel properties:
(i) Fuel composition per ASTM D 1945-91 ``Standard Test Method for
Analysis of Natural Gas By Gas Chromatography.'' This incorporation by
reference was approved by the Director of the Federal Register in
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be
obtained from the American Society for Testing and Materials, 100 Barr
Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959. Copies
may be inspected at U.S. EPA Headquarters Library, EPA West Building,
Constitution Avenue and 14th Street, NW., Room 3340, Washington DC, or
at the National Archives and Records Administration (NARA). For
information on the availability of this material at NARA, call 202-741-
6030, or go to: http://www.archives.gov/federal--register/code--of--
federal--regulations/ibr--locations.html.
(ii) Specific gravity (based on fuel composition per ASTM D 1945-91
``Standard Test Method for Analysis of Natural Gas by Gas
Chromatography.'') This incorporation by reference was approved by the
Director of the Federal Register in accordance with 5 U.S.C. 552(a) and
1 CFR part 51. Copies may be obtained from the American Society for
Testing and Materials, 100 Barr Harbor Drive, P.O. Box C700, West
Conshohocken, PA 19428-2959. Copies may be inspected at U.S. EPA
Headquarters Library, EPA West Building, Constitution Avenue and 14th
Street, NW., Room 3340, Washington DC, or at the National Archives and
Records Administration (NARA). For information
[[Page 897]]
on the availability of this material at NARA, call 202-741-6030, or go
to: http://www.archives.gov/federal--register/code--of--federal--
regulations/ibr--locations.html.
(iii) Carbon weight fraction based on the carbon contained only in
the HC constituents of the fuel=weight of carbon in HC constituents
divided by the total weight of fuel.
(iv) Carbon weight fraction of fuel=total weight of carbon in the
fuel (i.e., includes carbon contained in HC and in CO2)
divided by total weight of fuel.
(g) Calculate separate FTP, highway, US06, SC03 and Cold temperature
FTP fuel economy from the grams/mile values for total HC, CO,
CO2 and, where applicable, CH3OH, HCHO, NMHC and
CH4 and, the test fuel's specific gravity, carbon weight
fraction, net heating value, and additionally for natural gas, the test
fuel's composition. The emission values (obtained per paragraph (a)
through (e) of this section, as applicable) used in each calculation of
this section shall be rounded in accordance with Sec. 86.094-
26(a)(6)(iii) or Sec. 86.1837-01 of this chapter as applicable. The
CO2 values (obtained per this section, as applicable) used in
each calculation of this section shall be rounded to the nearest gram/
mile. The specific gravity and the carbon weight fraction (obtained per
paragraph (f) of this section) shall be recorded using three places to
the right of the decimal point. The net heating value (obtained per
paragraph (f) of this section) shall be recorded to the nearest whole
Btu/lb.
(h)(1) For gasoline-fueled automobiles tested on test fuel specified
in Sec. 86.113-04(a), the fuel economy in miles per gallon is to be
calculated using the following equation:
mpg = (5174 x 10 \4\ x C x CWF x SG)/[((CWF x HC) + (0.429 x CO) +
(0.273 x CO2)) x ((0.6 x SG x NHV) + 5471)]
Where:
HC = Grams/mile HC as obtained in paragraph (g) of this section.
CO = Grams/mile CO as obtained in paragraph (g) of this section.
CO2 = Grams/mile CO2 as obtained in paragraph (g)
of this section.
CWF = Carbon weight fraction of test fuel as obtained in paragraph (g)
of this section.
NHV = Net heating value by mass of test fuel as obtained in paragraph
(g) of this section.
SG = Specific gravity of test fuel as obtained in paragraph (g) of this
section.
(2) Round the calculated result to the nearest 0.1 miles per gallon.
(i)(1) For diesel-fueled automobiles, calculate the fuel economy in
miles per gallon of diesel fuel by dividing 2778 by the sum of three
terms:
(i) (A) 0.866 multiplied by HC (in grams/miles as obtained in
paragraph (g) of this section) or
(B) zero, in the case of cold FTP diesel tests for which HC was not
collected, as permitted in Sec. 600.113-08(c);
(ii) 0.429 multiplied by CO (in grams/mile as obtained in paragraph
(g) of this section); and
(iii) 0.273 multiplied by CO2 (in grams/mile as obtained
in paragraph (g) of this section).
(2) Round the quotient to the nearest 0.1 mile per gallon.
(j) For methanol-fueled automobiles and automobiles designed to
operate on mixtures of gasoline and methanol, the fuel economy in miles
per gallon is to be calculated using the following equation:
mpg = (CWF x SG x 3781.8)/((CWFexHC x HC) + (0.429 x CO) +
(0.273 x CO2) + (0.375 x CH3OH) + (0.400 x HCHO))
Where:
CWF = Carbon weight fraction of the fuel as determined in paragraph
(f)(2)(ii) of this section.
SG = Specific gravity of the fuel as determined in paragraph (f)(2)(i)
of this section.
CWFexHC = Carbon weight fraction of exhaust hydrocarbons =
CWFg as determined in (f)(2)(ii) of this section
(for M100 fuel, CWFexHC = 0.866).
HC = Grams/mile HC as obtained in paragraph (g) of this section.
CO = Grams/mile CO as obtained in paragraph (g) of this section.
CO2 = Grams/mile CO2 as obtained in paragraph (g)
of this section.
CH3OH = Grams/mile CH3OH (methanol) as obtained in
paragraph (d) of this section.
HCHO = Grams/mile HCHO (formaldehyde) as obtained in paragraph (g) of
this section.
(k) For automobiles fueled with natural gas, the fuel economy in
miles per gallon of natural gas is to be calculated using the following
equation:
[[Page 898]]
[GRAPHIC] [TIFF OMITTED] TR27DE06.035
Where:
mpge=miles per equivalent gallon of natural gas.
CWFHC/NG=carbon weight fraction based on the hydrocarbon
constituents in the natural gas fuel as obtained in paragraph
(g) of this section.
DNG=density of the natural gas fuel [grams/ft3 at 68 [deg]F
(20 [deg]C) and 760 mm Hg (101.3 kPa)] pressure as obtained in
paragraph (g) of this section.
CH4, NMHC, CO, and CO2=weighted mass exhaust
emissions [grams/mile] for methane, non-methane HC, carbon
monoxide, and carbon dioxide as calculated in Sec. 600.113.
CWFNMHC=carbon weight fraction of the non-methane HC
constituents in the fuel as determined from the speciated fuel
composition per paragraph (f)(3) of this section.
CO2NG=grams of carbon dioxide in the natural gas fuel
consumed per mile of travel.
CO2NG=FCNG DNG WFCO2
Where:
[GRAPHIC] [TIFF OMITTED] TR27DE06.036
Where:
CWFNG = the carbon weight fraction of the natural gas fuel as
calculated in paragraph (f) of this section.
WFCO2 = weight fraction carbon dioxide of the natural gas
fuel calculated using the mole fractions and molecular weights
of the natural gas fuel constituents per ASTM D 1945-91
``Standard Test Method for Analysis of Natural Gas by Gas
Chromatography.'' This incorporation by reference was approved
by the Director of the Federal Register in accordance with 5
U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from
the American Society for Testing and Materials, 100 Barr
Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959.
Copies may be inspected at U.S. EPA Headquarters Library, EPA
West Building, Constitution Avenue and 14th Street, NW., Room
3340, Washington, DC, or at the National Archives and Records
Administration (NARA). For information on the availability of
this material at NARA, call 202-741-6030, or go to: http://
www.archives.gov/ federal--register/code-- of--federal--
regulations/ ibr--locations.html.
(l) Equations for fuels other than those specified in paragraphs (h)
through (k) of this section may be used with advance EPA approval.
[71 FR 77935, Dec. 27, 2006]