40 CFR § 1037.705 - Generating and calculating emission credits.
(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 with the following equation:
(c) As described in § 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, even if they are certified under this part and labeled accordingly.
(3) Vehicles not subject to the requirements of this part, such as those excluded under § 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.