[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: 40CFR600.114-08]

[Page 903-909]
 
                   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. 600.114-08  Vehicle-specific 5-cycle fuel economy calculations.

    This section applies to data used for fuel economy labeling under 
Subpart D of this part.
    (a) City fuel economy. For each vehicle tested under Sec. 600.010-
08(c)(i) and (ii), determine the 5-cycle city fuel economy using the 
following equation:
[GRAPHIC] [TIFF OMITTED] TR27DE06.037

Where:
[GRAPHIC] [TIFF OMITTED] TR27DE06.038

Where:
[GRAPHIC] [TIFF OMITTED] TR27DE06.039

Where:

Bag Y FEX = the fuel economy in miles per gallon of fuel 
          during the specified bag of the FTP test conducted at an 
          ambient temperature of 75 [deg]F or 20 [deg]F,

and,
[GRAPHIC] [TIFF OMITTED] TR27DE06.040


[[Page 904]]


Where:

US06 City FE = fuel economy in miles per gallon over the ``city'' 
          portion of the US06 test,
HFET FE = fuel economy in miles per gallon over the HFET test,
SC03 FE = fuel economy in miles per gallon over the SC03 test.
    (b) Highway fuel economy. (1) For each vehicle tested under 
Sec. Sec. 600.010-08(a) and (c)(1)(ii)(B), determine the 5-cycle 
highway fuel economy using the following equation:
[GRAPHIC] [TIFF OMITTED] TR27DE06.041

Where:
[GRAPHIC] [TIFF OMITTED] TR27DE06.042

Where:
[GRAPHIC] [TIFF OMITTED] TR27DE06.043

and,
[GRAPHIC] [TIFF OMITTED] TR27DE06.044

Where:

US06 Highway FE = fuel economy in mile per gallon over the highway 
          portion of the US06 test,
HFET FE = fuel economy in mile per gallon over the HFET test,
SC03 FE = fuel economy in mile per gallon over the SC03 test.

    (2) If the condition specified in Sec. 600.115-08(b)(2)(iii)(B) is 
met, in lieu of using the calculation in paragraph (b)(1) of this 
section, the manufacturer may optionally determine the highway fuel 
economy using the following modified 5-cycle equation which utilizes 
data from FTP, HFET, and US06 tests, and applies mathematic adjustments 
for Cold FTP and SC03 conditions:
    (i) Perform a US06 test in addition to the FTP and HFET tests.
    (ii) Determine the 5-cycle highway fuel economy according to the 
following formula:
[GRAPHIC] [TIFF OMITTED] TR27DE06.045


[[Page 905]]


Where:
[GRAPHIC] [TIFF OMITTED] TR27DE06.046

Where:
[GRAPHIC] [TIFF OMITTED] TR27DE06.047

Bag y FE75 = the fuel economy in miles per gallon of fuel 
          during the specified bag of the FTP test conducted at an 
          ambient temperature of 75 [deg]F.
          [GRAPHIC] [TIFF OMITTED] TR27DE06.048
          
Where:

US06 Highway FE = fuel economy in miles per gallon over the highway 
          portion of the US06 test.
HFET FE = fuel economy in miles per gallon over the HFET test.
US06 FE = fuel economy in miles per gallon over the entire US06 test.

    (c) Fuel economy calculations for hybrid electric vehicles. Under 
the requirements of Sec. 86.1811-04(n), hybrid electric vehicles are 
subject to California test methods which require FTP emission sampling 
for the 75 [deg]F FTP test over four phases (bags) of the UDDS (cold-
start, transient, warm-start, transient). Optionally, these four phases 
may be combined into two phases (phases 1 + 2 and phases 3 + 4). 
Calculations for these sampling methods follow.
    (1) Four-bag FTP equations. If the 4-bag sampling method is used, 
manufacturers may use the equations in paragraphs (a) and (b) of this 
section to determine city and highway fuel economy estimates. If this 
method is chosen, it must be used to determine both city and highway 
fuel economy. Optionally, the following calculations may be used, 
provided that they are used to determine both city and highway fuel 
economy:
    (i) City fuel economy.
    [GRAPHIC] [TIFF OMITTED] TR27DE06.049
    
Where:
[GRAPHIC] [TIFF OMITTED] TR27DE06.050


[[Page 906]]


Where:
[GRAPHIC] [TIFF OMITTED] TR27DE06.051

and
[GRAPHIC] [TIFF OMITTED] TR27DE06.052

    (B) Running FC (gallons per mile) =
    [GRAPHIC] [TIFF OMITTED] TR27DE06.053
    
Where:

US06 Highway FE = fuel economy in miles per gallon over the city portion 
          of the US06 test.
US06 Highway FE = fuel economy in miles per gallon over the Highway 
          portion of the US06 test.
HFET FE = fuel economy in miles per gallon over the HFET test.
SC03 FE = fuel economy in miles per gallon over the SC03 test.

    (ii) Highway fuel economy.
    [GRAPHIC] [TIFF OMITTED] TR27DE06.054
    
Where:
[GRAPHIC] [TIFF OMITTED] TR27DE06.055

Where:

[[Page 907]]

[GRAPHIC] [TIFF OMITTED] TR27DE06.056

[GRAPHIC] [TIFF OMITTED] TR27DE06.057

[GRAPHIC] [TIFF OMITTED] TR27DE06.058

Where:
US06 Highway FE = fuel economy in miles per gallon over the Highway 
          portion of the US06 test,
HFET FE = fuel economy in miles per gallon over the HFET test,
SC03 FE = fuel economy in miles per gallon over the SC03 test.

    (2) Two-bag FTP equations. If the 2-bag sampling method is used for 
the 75 [deg]F FTP test, it must be used to determine both city and 
highway fuel economy. The following calculations must be used to 
determine both city and highway fuel economy:
    (i) City fuel economy.
    [GRAPHIC] [TIFF OMITTED] TR27DE06.059
    
Where:
[GRAPHIC] [TIFF OMITTED] TR27DE06.060

Where:
[GRAPHIC] [TIFF OMITTED] TR27DE06.061

[GRAPHIC] [TIFF OMITTED] TR27DE06.062

Where:
Bag y FE20 = the fuel economy in miles per gallon of fuel 
          during Bag 1 or Bag 3 of the 20 [deg]F FTP test.
Bag x/y FEX = fuel economy in miles per gallon of fuel during 
          combined phases 1 and 2 or phases 3 and 4 of the FTP test 
          conducted at an ambient temperature of 75 [deg]F.

[[Page 908]]

[GRAPHIC] [TIFF OMITTED] TR27DE06.063

Where:
US06 City FE = fuel economy in miles per gallon over the city portion of 
          the US06 test,
SC03 FE = fuel economy in miles per gallon over the SC03 test.
Bag x/y FEX = fuel economy in miles per gallon of fuel during 
          combined phases 1 and 2 or phases 3 and 4 of the FTP test 
          conducted at an ambient temperature of 75 [deg]F.
    (ii) Highway fuel economy.
    [GRAPHIC] [TIFF OMITTED] TR27DE06.064
    
Where:
[GRAPHIC] [TIFF OMITTED] TR27DE06.065

Where:
[GRAPHIC] [TIFF OMITTED] TR27DE06.066

and
[GRAPHIC] [TIFF OMITTED] TR27DE06.067

and
[GRAPHIC] [TIFF OMITTED] TR27DE06.068


[[Page 909]]


Where:
US06 Highway FE = fuel economy in miles per gallon over the city portion 
          of the US06 test,
SC03 FE = fuel economy in miles per gallon over the SC03 test.
Bag y FE20 = the fuel economy in miles per gallon of fuel 
          during Bag 1 or Bag 3 of the 20 [deg]F FTP test.
Bag x/y FEX = fuel economy in miles per gallon of fuel during 
          phases 1 and 2 or phases 3 and 4 of the FTP test conducted at 
          an ambient temperature of 75 [deg]F.

    (3) For hybrid electric vehicles using the modified 5-cycle highway 
calculation in paragraph (b)(2) of this section, the equation in 
paragraph (b)(2)(ii)(A) of this section, applies except that the 
equation for Start Fuel75 will be replaced with one of the 
following:
    (i) The equation for Start Fuel75 for hybrids tested 
according to the 4-bag FTP is:
[GRAPHIC] [TIFF OMITTED] TR27DE06.069

    (ii) The equation for Start Fuel75 for hybrids tested 
according to the 2-bag FTP is:
[GRAPHIC] [TIFF OMITTED] TR27DE06.070


[71 FR 77938, Dec. 27, 2006; 72 FR 20403, Apr. 24, 2007]