Section 537.4 - Definitions(a)Statutory terms.(1) The terms average fuel economy standard, fuel, manufacture, and model year are used as defined in 49 U.S.C. 32901 .(2) The term manufacturer is used as defined in 49 U.S.C. 32901 and in accordance with part 529 of this chapter.(3) The terms average fuel economy, fuel economy, and model type are used as defined in subpart A of 40 CFR part 600.(4) The terms automobile, automobile capable of off-highway operation, and passenger automobile are used as defined in 49 U.S.C. 32901 and in accordance with the determinations in part 523 of this chapter.(b)Other terms.(1) The term loaded vehicle weight is used as defined in subpart A of 40 CFR part 86.(2) The terms axle ratio, base level, body style, car line, combined fuel economy, engine code, equivalent test weight, gross vehicle weight, inertia weight, transmission class, and vehicle configuration are used as defined in subpart A of 40 CFR part 600.(3) The term light truck is used as defined in part 523 of this chapter and in accordance with determinations in that part.(4) The terms approach angle, axle clearance, brakeover angle, cargo carrying volume, departure angle, passenger carrying volume, running clearance, and temporary living quarters are used as defined in part 523 of this chapter.(5) The term incomplete automobile manufacturer is used as defined in part 529 of this chapter.(6) As used in this part, unless otherwise required by the context:(i)Administrator means the Administrator of the National Highway Traffic Safety Administration or the Administrator's delegate.(ii)Current model year means:(A) In the case of a pre-model year report, the full model year immediately following the period during which that report is required by § 537.5(b) to be submitted.(B) In the case of a mid-model year report, the model year during which that report is required by § 537.5(b) to be submitted.(iii)Average means a production-weighted harmonic average.(iv)Total drive ratio means the ratio of an automobile's engine rotational speed (in revolutions per minute) to the automobile's forward speed (in miles per hour). 87 FR 26070 , 7/1/2022; 89 FR 52953 , 8/23/2024