# 40 C.F.R. § 86.001-2 (2026): Definitions > Federal · Regulations · In force URL: https://www.frixlaw.com/law-library/statutes/CFR_T40_P86_S86_001_2 ## Section - **Citation:** 40 C.F.R. § 86.001-2 (2026) - **Heading:** Definitions - **Jurisdiction:** Federal - **Kind:** Regulations - **Status:** In force - **Text as of:** August 14, 2026 - **Source:** Compiled text - **Location:** Title 40 CFR: Protection of Environment / Chapter I / Part 86 / Subpart A / § 86.001-2: § 86.001-2 Definitions. ## 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 ion 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 C.F.R. § 86.000-2 (2026) § 86.000-2 Definitions.](https://www.frixlaw.com/law-library/statutes/CFR_T40_P86_S86_000_2.md) - [40 C.F.R. § 86.000-3 (2026) § 86.000-3 Abbreviations.](https://www.frixlaw.com/law-library/statutes/CFR_T40_P86_S86_000_3.md) - [40 C.F.R. § 86.000-7 (2026) § 86.000-7 Maintenance of records; submittal of information; right of entry.](https://www.frixlaw.com/law-library/statutes/CFR_T40_P86_S86_000_7.md) - [40 C.F.R. § 86.000-24 (2026) § 86.000-24 Test vehicles and engines.](https://www.frixlaw.com/law-library/statutes/CFR_T40_P86_S86_000_24.md) - [40 C.F.R. § 86.001-2 (2026) § 86.001-2 Definitions.](https://www.frixlaw.com/law-library/statutes/CFR_T40_P86_S86_001_2.md) - [40 C.F.R. § 86.001-21 (2026) § 86.001-21 Application for certification.](https://www.frixlaw.com/law-library/statutes/CFR_T40_P86_S86_001_21.md) - [40 C.F.R. § 86.001-23 (2026) § 86.001-23 Required data.](https://www.frixlaw.com/law-library/statutes/CFR_T40_P86_S86_001_23.md) - [40 C.F.R. § 86.001-24 (2026) § 86.001-24 Test vehicles and engines.](https://www.frixlaw.com/law-library/statutes/CFR_T40_P86_S86_001_24.md) - [40 C.F.R. § 86.004-2 (2026) § 86.004-2 Definitions.](https://www.frixlaw.com/law-library/statutes/CFR_T40_P86_S86_004_2.md) - [40 C.F.R. § 86.004-11 (2026) § 86.004-11 Emission standards for 2004 and later model year diesel heavy-duty engines and vehicles.](https://www.frixlaw.com/law-library/statutes/CFR_T40_P86_S86_004_11.md) - [40 C.F.R. § 86.004-15 (2026) § 86.004-15 NO X plus NMHC and particulate averaging, trading, and banking for heavy-duty engines.](https://www.frixlaw.com/law-library/statutes/CFR_T40_P86_S86_004_15.md) - [40 C.F.R. § 86.004-16 (2026) § 86.004-16 Prohibition of defeat devices.](https://www.frixlaw.com/law-library/statutes/CFR_T40_P86_S86_004_16.md) - [40 C.F.R. § 86.004-21 (2026) § 86.004-21 Application for certification.](https://www.frixlaw.com/law-library/statutes/CFR_T40_P86_S86_004_21.md) - [40 C.F.R. § 86.004-25 (2026) § 86.004-25 Maintenance.](https://www.frixlaw.com/law-library/statutes/CFR_T40_P86_S86_004_25.md) --- Source: Frix Law Library, https://www.frixlaw.com/law-library/statutes/CFR_T40_P86_S86_001_2. 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