# 40 CFR § 86.001-2: Definitions

> Federal · Regulations · In force

URL: https://www.frixlaw.com/law-library/statutes/ecfr-40-86.001-2

## Section

- **Citation:** 40 CFR § 86.001-2
- **Heading:** Definitions
- **Jurisdiction:** Federal
- **Kind:** Regulations
- **Status:** In force
- **Text as of:** September 22, 2026
- **Source:** Publisher's official text
- **Location:** Title 40—Protection of Environment > CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY > SUBCHAPTER C—AIR PROGRAMS > PART 86—CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES > Subpart A—General Provisions for Heavy-Duty Engines and Heavy-Duty Vehicles

## Text

The definitions of § 86.000-2 continue to apply to 2000 and later model year vehicles. The definitions listed in this section apply beginning with the 2001 model year.
Useful life means:
(1) For light-duty vehicles, and for light light-duty trucks not subject to the Tier 0 standards of § 86.094-9(a), intermediate useful life and/or full useful life. Intermediate useful life is a period of use of 5 years or 50,000 miles, whichever occurs first. Full useful life is a period of use of 10 years or 100,000 miles, whichever occurs first, except as otherwise noted in § 86.094-9. The useful life of evaporative and/or refueling emission control systems on the portion of these vehicles subject to the evaporative emission test requirements of § 86.130-96, and/or the refueling emission test requirements of § 86.151-2001, is defined as a period of use of 10 years or 100,000 miles, whichever occurs first.
(2) For light light-duty trucks subject to the Tier 0 standards of § 86.094-9(a), and for heavy light-duty truck engine families, intermediate and/or full useful life. Intermediate useful life is a period of use of 5 years or 50,000 miles, whichever occurs first. Full useful life is a period of use of 11 years or 120,000 miles, whichever occurs first. The useful life of evaporative emission and/or refueling control systems on the portion of these vehicles subject to the evaporative emission test requirements of § 86.130-96, and/or the refueling emission test requirements of § 86.151-2001, is also defined as a period of 11 years or 120,000 miles, whichever occurs first.
(3) For an Otto-cycle heavy-duty engine family:
(i) For hydrocarbon and carbon monoxide standards, a period of use of 8 years or 110,000 miles, whichever first occurs.
(ii) For the oxides of nitrogen standard, a period of use of 10 years or 110,000 miles, whichever first occurs.
(iii) For the portion of evaporative emission control systems subject to the evaporative emission test requirements of § 86.1230-96, a period of use of 10 years or 110,000 miles, whichever occurs first.
(4) For a diesel heavy-duty engine family:
(i) For light heavy-duty diesel engines, for hydrocarbon, carbon monoxide, and particulate standards, a period of use of 8 years or 110,000 miles, whichever first occurs.
(ii) For light heavy-duty diesel engines, for the oxides of nitrogen standard, a period of use of 10 years or 110,000 miles, whichever first occurs.
(iii) For medium heavy-duty diesel engines, for hydrocarbon, carbon monoxide, and particulate standards, a period of use of 8 years or 185,000 miles, whichever first occurs.
(iv) For medium heavy-duty diesel engines, for the oxides of nitrogen standard, a period of use of 10 years or 185,000 miles, whichever first occurs.
(v) For heavy heavy-duty diesel engines, for hydrocarbon, carbon monoxide, and particulate standards, a period of use of 8 years or 290,000 miles, whichever first occurs, except as provided in paragraph (4)(vii) of this definition.
(vi) For heavy heavy-duty diesel engines, for the oxides of nitrogen standard, a period of use of 10 years or 290,000 miles, whichever first occurs.
(vii) For heavy heavy-duty diesel engines used in urban buses, for the particulate standard, a period of use of 10 years or 290,000 miles, whichever first occurs.
[59 FR 16281, Apr. 6, 1994, as amended at 61 FR 54886, Oct. 22, 1996]

## Nearby sections

- [40 CFR § 86.000-2 § 86.000-2 Definitions.](https://www.frixlaw.com/law-library/statutes/ecfr-40-86.000-2.md)
- [40 CFR § 86.000-3 § 86.000-3 Abbreviations.](https://www.frixlaw.com/law-library/statutes/ecfr-40-86.000-3.md)
- [40 CFR § 86.000-7 § 86.000-7 Maintenance of records; submittal of information; right of entry.](https://www.frixlaw.com/law-library/statutes/ecfr-40-86.000-7.md)
- [40 CFR § 86.000-24 § 86.000-24 Test vehicles and engines.](https://www.frixlaw.com/law-library/statutes/ecfr-40-86.000-24.md)
- [40 CFR § 86.001-2 § 86.001-2 Definitions.](https://www.frixlaw.com/law-library/statutes/ecfr-40-86.001-2.md)
- [40 CFR § 86.001-21 § 86.001-21 Application for certification.](https://www.frixlaw.com/law-library/statutes/ecfr-40-86.001-21.md)
- [40 CFR § 86.001-23 § 86.001-23 Required data.](https://www.frixlaw.com/law-library/statutes/ecfr-40-86.001-23.md)
- [40 CFR § 86.001-24 § 86.001-24 Test vehicles and engines.](https://www.frixlaw.com/law-library/statutes/ecfr-40-86.001-24.md)
- [40 CFR § 86.004-2 § 86.004-2 Definitions.](https://www.frixlaw.com/law-library/statutes/ecfr-40-86.004-2.md)
- [40 CFR § 86.004-11 § 86.004-11 Emission standards for 2004 and later model year diesel heavy-duty engines and vehicles.](https://www.frixlaw.com/law-library/statutes/ecfr-40-86.004-11.md)
- [40 CFR § 86.004-15 § 86.004-15 NOX plus NMHC and particulate averaging, trading, and banking for heavy-duty engines.](https://www.frixlaw.com/law-library/statutes/ecfr-40-86.004-15.md)
- [40 CFR § 86.004-16 § 86.004-16 Prohibition of defeat devices.](https://www.frixlaw.com/law-library/statutes/ecfr-40-86.004-16.md)
- [40 CFR § 86.004-21 § 86.004-21 Application for certification.](https://www.frixlaw.com/law-library/statutes/ecfr-40-86.004-21.md)
- [40 CFR § 86.004-25 § 86.004-25 Maintenance.](https://www.frixlaw.com/law-library/statutes/ecfr-40-86.004-25.md)

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Source: Frix Law Library, https://www.frixlaw.com/law-library/statutes/ecfr-40-86.001-2. Check the current official text before relying on it. Not legal advice.