(a) The provisions of this section apply separately for calculating emission credits for each pollutant.
(b) For each participating family or subfamily, calculate positive or negative emission credits relative to the otherwise applicable emission standard. Calculate positive emission credits for a family or subfamily that has an FEL below the standard. Calculate negative emission credits for a family or subfamily that has an FEL above the standard. Sum your positive and negative credits for the model year before rounding. Round the sum of emission credits to the nearest megagram (Mg), using consistent units throughout the following equations:
(1) For vocational vehicles: Emission credits (Mg) = (Std-FEL) x (Payload Tons) x (Volume) x (UL) x (10-6) Where: Std = the emission standard associated with the specific tractor
regulatory subcategory (g/ton-mile).FEL = the family emission limit for the vehicle subfamily (g/ton-mile).Payload tons = the prescribed payload for each class in tons (2.85 tons
for light heavy-duty vehicles, 5.6 tons for medium heavy-duty
vehicles, and 7.5 tons for heavy heavy-duty vehicles).Volume = U.S.-directed production volume of the vehicle subfamily. For
example, if you produce three configurations with the same
FEL, the subfamily production volume would be the sum of the
production volumes for these three configurations.UL = useful life of the vehicle (110,000 miles for light heavy-duty
vehicles, 185,000 miles for medium heavy-duty vehicles, and
435,000 miles for heavy heavy-duty vehicles).
(2) For tractors: Emission credits (Mg) = (Std-FEL) x (Payload tons) x (Volume) x (UL) x (10-6) Where: Std = the emission standard associated with the specific tractor
regulatory subcategory (g/ton-mile).FEL = the family emission limit for the vehicle subfamily (g/ton-mile).Payload tons = the prescribed payload for each class in tons (12.5 tons
for Class 7 and 19 tons for Class 8).Volume = U.S.-directed production volume of the vehicle subfamily.UL = useful life of the tractor (435,000 miles for Class 8 and 185,000
miles for Class 7).
(c) As described in Sec. 1037.730, compliance with the requirements of this subpart is determined at the end of the model year based on actual U.S.-directed production volumes. Keep appropriate records to document these production volumes. Do not include any of the following vehicles to calculate emission credits:
(1) Vehicles that you do not certify to the CO2 standards of this part because they are permanently exempted under subpart G of this part or under 40 CFR part 1068.
(2) Exported vehicles.
(3) Vehicles not subject to the requirements of this part, such as those excluded under Sec. 1037.5.
(4) Any other vehicles, where we indicate elsewhere in this part 1037 that they are not to be included in the calculations of this subpart.