Fuel economy means:
(1) The average number of miles traveled by an automobile or group of automobiles per volume of fuel consumed as calculated in this part; or
(2) For the purpose of calculating average fuel economy pursuant to the provisions of part 600, subpart F, fuel economy for electrically powered automobiles means the equivalent petroleum-based fuel economy as determined by the Secretary of Energy in accordance with the provisions of 10 CFR 474. For the purpose of labeling pursuant to the provisions of part 600, subpart D, the term means the fuel economy value as determined by the procedures specified in § 600.116-12.
40 CFR § 600.002
The following definitions apply throughout this part: