Petroleum-equivalent fuel economy calculation.

(a) The petroleum-equivalent fuel economy for an electric vehicle is calculated as follows: (1) Determine the electric vehicle's Urban Dynamometer Driving Schedule energy consumption value and the Highway Fuel Economy Driving Schedule energy consumption value in units of Watt-hours per mile; (2) Determine the combined energy consumption value by averaging the Urban Dynamometer Driving Schedule energy consumption value and the Highway Fuel Economy Driving Schedule energy consumption value using a weighting of 55 percent urban/45 percent highway; and (3) Calculate the petroleum-equivalent fuel economy by dividing the appropriate petroleum-equivalency factor (depending on whether any petroleum-powered accessories are installed; see paragraph (b) of this section) by the combined energy consumption value, and round to the nearest 0.01 miles per gallon. (b) The petroleum-equivalency factors for electric vehicles are as follows: (1) If the electric vehicle does not have any petroleum-powered accessories installed, the value of the petroleum equivalency factor is 12,307 Watt-hours per gallon. (2) If the electric vehicle has any petroleum-powered accessories installed, the value of the petroleum-equivalency factor is 11,706 Watt-hours per gallon. [65 FR 36991, June 12, 2000, as amended at 89 FR 22059, Mar. 29, 2024; 91 FR 554, Jan. 8, 2026; 91 FR 7817, Feb. 19, 2026]