49 C.F.R. § 525.4
(a) Statutory terms.
(b) Other terms.
(7) As used in this part, unless otherwise required by the context:
Act means the Motor Vehicle Information and Cost Savings Act (Pub. L. 92-513), as amended by the Energy Policy and Conservation Act (Pub. L. 94-163);
Administrator means the Administrator of the National Highway Traffic Safety Administration;
Affected model year means a model year for which an exemption and alternative average fuel economy standard are requested under this part;
Production mix means the number of passenger automobiles, and their percentage of the petitioner's annual total production of passenger automobiles, in each vehicle configuration which a petitioner plans to manufacture in a model year; and
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).
(Authority: Sec. 301, Pub. L. 94-163, 89 Stat. 871 (15 U.S.C. 2002); delegation of authority at 41 FR 25015, June 22, 1976; sec. 9, Pub. L. 89-670, 80 Stat. 981 (49 U.S.C. 1657))
[42 FR 38376, July 28, 1977, as amended at 44 FR 55579, Sept. 27, 1979]