comparable conventionally fueled motor vehicle
(4) the term “comparable conventionally fueled motor vehicle” means a motor vehicle which is, as determined by the Secretary— (A) commercially available at the time the comparability of the vehicle is being assessed; (B) powered by an internal combustion engine that utilizes gasoline or diesel fuel as its fuel source; and (C) provides passenger capacity or payload capacity the same or similar to the alternative fueled vehicle to which it is being compared;