---
kind: "section"
citation: "49 C.F.R. § 531.4"
title: "49"
number: "531.4"
heading: "Definitions."
url: "https://uscodex.org/cfr/49/531.4"
---

# §531.4. Definitions.

- (a) **Statutory terms.**
  - (1) The terms average fuel economy, manufacture, manufacturer, and model year are used as defined in [49 U.S.C. 32901](/usc/49/32901.md).
  - (2) The terms automobile and passenger automobile are used as defined in [49 U.S.C. 32901](/usc/49/32901.md) and in accordance with the determination in [part 523](/cfr/49/part523.md) of this chapter.
- (b) **Other terms.** As used in this part, unless otherwise required by the context—
  - (1) The term domestically manufactured passenger automobile means the vehicle is deemed to be manufactured domestically under 49 U.S.C. [32904(b)(3)](/usc/49/32904.md?p=b-3) and [40](/usc/49/40.md) CFR 600.511-08.
  - (2) [Reserved]

## Notes

### Amendments

[89 FR 52945, June 24, 2024]

### Authority

Authority: 49 U.S.C. 32902, delegation of authority at 49 CFR 1.95.

### Source

Source: 87 FR 26070, May 2, 2022, unless otherwise noted.

### Amendments

[89 FR 52945, June 24, 2024]