[Title 40 CFR 600.510]
[Code of Federal Regulations (annual edition) - July 1, 1996 Edition]
[Title 40 - PROTECTION OF ENVIRONMENT]
[Chapter I - ENVIRONMENTAL PROTECTION AGENCY (Continued)]
[Subchapter Q - ENERGY POLICY]
[Part 600 - FUEL ECONOMY OF MOTOR VEHICLES]
[Subpart F - Fuel Economy Regulations for Model Year 1978 Passenger]
[Sec. 600.510 - 86 Calculation of average fuel economy.]
[From the U.S. Government Printing Office]


40PROTECTION OF ENVIRONMENT161996-07-011996-07-01false86 Calculation of average fuel economy.600.510Sec. 600.510PROTECTION OF ENVIRONMENTENVIRONMENTAL PROTECTION AGENCY (Continued)ENERGY POLICYFUEL ECONOMY OF MOTOR VEHICLESFuel Economy Regulations for Model Year 1978 Passenger
Sec. 600.510-86  Calculation of average fuel economy.

    (a) Average fuel economy will be calculated to the nearest 0.1 mpg 
for the classes of automobiles identified herein, and the results of 
such calculations will be reported to the Secretary of Transportation 
for use in determining compliance with the applicable fuel economy 
standards.
    (1) An average fuel economy calculation will be made for the 
category of passenger automobiles that is domestically manufactured as 
defined in Sec. 600.511(d)(1).
    (2) An average fuel economy calculation will be made for the 
category of passenger automobiles that is not domestically manufactured 
as defined in Sec. 600.511(d)(2).
    (3) An average fuel economy calculation will be made for the 
category of light trucks which is defined in Sec. 600.511(e)(1) and has 
two-wheel drive.
    (4) An average fuel economy calculation will be made for the 
category of light trucks which is defined in Sec. 600.511(e)(1) and has 
four-wheel drive.
    (5) An average fuel economy calculation will be made for the 
category of

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light trucks which is defined in Sec. 600.511(e)(2) and has two-wheel 
drive.
    (6) An average fuel economy calculation will be made for the 
category of light trucks which is defined in Sec. 600.511(e)(2) and has 
four-wheel drive.
    (b) For the purpose of calculating average fuel economy under 
paragraph (c), of this section:
    (1) All fuel economy data submitted in accordance with 
Sec. 600.006(e) or Sec. 600.512(c) shall be used.
    (2) The combined city/highway fuel economy will be calculated for 
each model type in accordance with Sec. 600.207 of this section except 
that:
    (i) Separate fuel economy values will be calculated for model types 
and base levels associated with car lines that are:
    (A) Domestically produced, and
    (B) Nondomestically produced and imported;
    (ii) Total model year production data, as required by this subpart, 
will be used instead of sales projections;
    (iii) The fuel economy value of diesel-powered model types will be 
multiplied by the factor 1.0 to correct gallons of diesel fuel to 
equivalent gallons of gasoline;
    (iv) The fuel economy value will be rounded to the nearest 0.1 mpg;
    (v) At the manufacturer's option, those vehicle configurations that 
are selfcompensating to altitude changes may be separated by sales into 
high-altitude sales categories and low-altitude sales categories. These 
separate sales categories may then be treated (only for the purpose of 
this section) as separate configurations in accordance with the 
procedure of paragraph Sec. 600.207(a)(4)(ii), and
    (3) The fuel economy value for each vehicle configuration is the 
combined fuel economy calculated according to Sec. 600.206 except that:
    (i) Separate fuel economy values will be calculated for vehicle 
configurations associated with car lines that are:
    (A) Domestically produced, and
    (B) Nondomestically produced and imported:
    (ii) Total model year production data, as required by this subpart 
will be used instead of sales projections; and
    (iii) The fuel economy value of diesel-powered model types will be 
multiplied by the factor 1.0 to convert gallons of diesel fuel to 
equivalent gallons of gasoline.
    (c) Except as permitted in paragraph (d) of this section, the 
average fuel economy will be calculated individually for each category 
identified in Sec. 600.510(a) as follows:
    (1) Divide the total production volume of that category of 
automobiles by
    (2) A sum of terms, each of which corresponds to a model type within 
that category of automobiles and is a fraction determined by dividing
    (i) The number of automobiles of that model type produced by the 
manufacturer in the model year by
    (ii) The fuel economy calculated for that model type in accordance 
with paragraph (b)(2) of this section.
    (d) The Administrator may approve alternative calculation methods if 
they are part of an approved credit plan under the provisions of section 
503(b) of U.S.C. 2003(b).
    (e) For passenger categories identified in paragraphs (a) (1) and 
(2) of this section, the average fuel economy calculated in accordance 
with paragraph (c) of this section shall be adjusted using the following 
equation:

AFEadj = AFE[((0.55 x a x c) + (0.45 x c) + (0.5556 x a) + 0.4487)/
          ((0.55 x a) + 0.45)] +   IW
Where:

AFEajd=Adjusted average combined fuel economy, rounded to the 
          nearest 0.1 mpg.
AFE=Average combined fuel economy as calculated in paragraph (c) of this 
          section, rounded to the nearest 0.0001 mpg.
a=Sales-weighted average (rounded to the nearest 0.0001 mpg) of all 
          model type highway fuel economy values (rounded to the nearest 
          0.1 mpg) divided by the sales-weighted average (rounded to the 
          nearest 0.0001 mpg) of all model type city fuel economy values 
          (rounded to the nearest 0.1 mpg). The quotient shall be 
          rounded to 4 decimal places. These average fuel economies 
          shall be determined using the methodology of paragraph (c) of 
          this section.
c=0.0022 for the 1986 model year.
c=A constant value, fixed by model year. For 1987, the Administrator 
          will specify the c value after the necessary laboratory 
          humidity and test fuel data become available. For 1988 and 
          later model years, the Administrator will specify the c value 
          after the necessary laboratory humidity and test fuel data 
          become available.

[[Page 740]]

IW=(9.2917 x 10-3 x SF3 IWC x FE3 IWC) 
          -(3.5123 x 10-3 x SF4 ETW x FE4 IWC)

    Note: Any calculated value of IW less than zero shall be set equal 
to zero.

SF3 IWC=The 3000 lb. inertia weight class sales divided by total 
          sales. The quotient shall be rounded to 4 decimal places.
SF4 ETW=The 4000 lb. equivalent test weight category sales divided 
          by total sales. The quotient shall be rounded to 4 decimal 
          places.
FE4 IWC=The sales-weighted average combined fuel economy of all 
          3000 lb. inertia weight class base leves in the compliance 
          category. Round the result to the nearest 0.0001 mpg.
FE4 IWC=The sales-weighted average combined fuel economy of all 
          4000 lb. inertia weight class base levels in the compliance 
          category. Round the result to the nearest 0.0001 mpg.

    (f) The Administration shall calculate and apply additional average 
fuel ecomony adjustments if, after notice and opportunity for comment, 
the Administrator determines that, as a result of test procedure changes 
not previously considered, such correction is necessary to yield fuel 
economy test results that are comparable to those obtained under the 
1975 test procedures. In making such determinations, the Administrator 
must find that:
    (1) A directional change in measured fuel economy of an average 
vehicle can be predicted from a revision to the test procedures;
    (2) The magnitude of the change in measured fuel economy for any 
vehicle or fleet of vehicles caused by a revision to the test procedures 
is quantifiable from theoretical calculations or best available test 
data;
    (3) The impact of a change on average fuel economy is not due to 
eliminating the ability of manufacturers to take advantage of 
flexibilities within the existing test procedures to gain measured 
improvements in fuel economy which are not the result of actual 
improvements in the fuel economy of production vehicles.
    (4) The impact of a change on average fuel economy is not solely due 
to a greater ability of manufacturers to reflect in average fuel economy 
those design changes expected to have comparable effect on in-use fuel 
economy.
    (5) The test procedure change is required by EPA or is a change 
initiated by EPA in its laboratory and is not a change implemented 
solely by a manufacturer in its own laboratory.

[49 FR 13854, Apr. 6, 1984, as amended at 50 FR 27186, July 1, 1985; 51 
FR 37851, Oct. 24, 1986]