---
kind: "section"
citation: "49 C.F.R. § 538.4"
title: "49"
number: "538.4"
heading: "Definitions."
url: "https://uscodex.org/cfr/49/538.4"
---

# §538.4. Definitions.

- (a) **Statutory terms.**
  - (1) The terms alternative fuel, alternative fueled automobile, and dual fueled automobile, are used as defined in [49 U.S.C. 32901(a)](/usc/49/32901.md?p=a).
  - (2) The terms automobile and passenger automobile, are used as defined in [49 U.S.C. 32901(a)](/usc/49/32901.md?p=a), and in accordance with the determinations in [part 523](/cfr/49/part523.md) of this chapter.
  - (3) The term manufacturer is used as defined in [49 U.S.C. 32901(a)(13)](/usc/49/32901.md?p=a-13), and in accordance with [part 529](/cfr/49/part529.md) of this chapter.
  - (4) The term model year is used as defined in [49 U.S.C. 32901(a)(15)](/usc/49/32901.md?p=a-15).
- (b)
  - (1) **Other terms.** The terms average fuel economy, fuel economy, and model type are used as defined in [subpart A](/cfr/49/subpartA.md) of [40 CFR part 600](/cfr/40/part600.md).
  - (2) The term EPA means the U.S. Environmental Protection Agency.

## Notes

### Authority

Authority: 49 U.S.C. 32901, 32905, and 32906; delegation of authority at 49 CFR 1.95.

### Source

Source: 61 FR 14511, Apr. 2, 1996, unless otherwise noted.