republic-os/legal/us/code/title-42/chapter-85/section-7549.md

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LegalText	42 U.S.C. § 7549	High altitude performance adjustments	us	united_states_code	code_section	42	THE PUBLIC HEALTH AND WELFARE	85	AIR POLLUTION PREVENTION AND CONTROL	7549	42 U.S.C. § 7549	current	119-100	2026-06-26	official	https://uscode.house.gov/download/releasepoints/us/pl/119/100/xml_usc42@119-100.zip	/us/usc/t42/s7549	data/legal/raw/us/code/title-42/usc42.xml	24af6fb8fceff6f1e7bf1e900f746cdf9de0d3800c1bc09d23dc34ab7b44f22d	644321055a08eb1f260a6a3e31ac157fa024756abf612a9fd6857e7e400cf24e	5a12765ec56335feb5633b5ef66cd20d55e5ce9149857d9258c918a016b2faba	2026-07-04	official	legal us-code

42 U.S.C. § 7549 - High altitude performance adjustments

Text

(a) Instruction of the manufacturer (1) Any action taken with respect to any element of design installed on or in a motor vehicle or motor vehicle engine in compliance with regulations under this subchapter (including any alteration or adjustment of such element), shall be treated as not in violation of section 7522(a) of this title if such action is performed in accordance with high altitude adjustment instructions provided by the manufacturer under subsection (b) and approved by the Administrator.

(2) If the Administrator finds that adjustments or modifications made pursuant to instructions of the manufacturer under paragraph (1) will not insure emission control performance with respect to each standard under section 7521 of this title at least equivalent to that which would result if no such adjustments or modifications were made, he shall disapprove such instructions. Such finding shall be based upon minimum engineering evaluations consistent with good engineering practice.

(b) Regulations (1) Instructions respecting each class or category of vehicles or engines to which this subchapter applies providing for such vehicle and engine adjustments and modifications as may be necessary to insure emission control performance at different altitudes shall be submitted by the manufacturer to the Administrator pursuant to regulations promulgated by the Administrator.

(2) Any knowing violation by a manufacturer of requirements of the Administrator under paragraph (1) shall be treated as a violation by such manufacturer of section 7522(a)(3) of this title for purposes of the penalties contained in section 7524 of this title.

(3) Such instructions shall provide, in addition to other adjustments, for adjustments for vehicles moving from high altitude areas to low altitude areas after the initial registration of such vehicles.

(c) Manufacturer parts No instructions under this section respecting adjustments or modifications may require the use of any manufacturer parts (as defined in section 7522(a) of this title) unless the manufacturer demonstrates to the satisfaction of the Administrator that the use of such manufacturer parts is necessary to insure emission control performance.

(d) State inspection and maintenance programs Before January 1, 1981 the authority provided by this section shall be available in any high altitude State (as determined under regulations of the Administrator under regulations promulgated before August 7, 1977) but after December 31, 1980, such authority shall be available only in any such State in which an inspection and maintenance program for the testing of motor vehicle emissions has been instituted for the portions of the State where any national ambient air quality standard for auto-related pollutants has not been attained.

(e) High altitude testing (1) The Administrator shall promptly establish at least one testing center (in addition to the testing centers existing on November 15, 1990) located at a site that represents high altitude conditions, to ascertain in a reasonable manner whether, when in actual use throughout their useful life (as determined under section 7521(d) of this title), each class or category of vehicle and engines to which regulations under section 7521 of this title apply conforms to the emissions standards established by such regulations. For purposes of this subsection, the term “high altitude conditions” refers to high altitude as defined in regulations of the Administrator in effect as of November 15, 1990.

(2) The Administrator, in cooperation with the Secretary of Energy and the Administrator of the Federal Transit Administration, and such other agencies as the Administrator deems appropriate, shall establish a research and technology assessment center to provide for the development and evaluation of less-polluting heavy-duty engines and fuels for use in buses, heavy-duty trucks, and non-road engines and vehicles, which shall be located at a high-altitude site that represents high-altitude conditions. In establishing and funding such a center, the Administrator shall give preference to proposals which provide for local cost-sharing of facilities and recovery of costs of operation through utilization of such facility for the purposes of this section.

(3) The Administrator shall designate at least one center at high-altitude conditions to provide research on after-market emission components, dual-fueled vehicles and conversion kits, the effects of tampering on emissions equipment, testing of alternate fuels and conversion kits, and the development of curricula, training courses, and materials to maximize the effectiveness of inspection and maintenance programs as they relate to promoting effective control of vehicle emissions at high-altitude elevations. Preference shall be given to existing vehicle emissions testing and research centers that have established reputations for vehicle emissions research and development and training, and that possess in-house Federal Test Procedure capacity.

(July 14, 1955, ch. 360, title II, § 215, as added Pub. L. 95–95, title II, § 211(b), Aug. 7, 1977, 91 Stat. 757; amended Pub. L. 95–190, § 14(a)(75), Nov. 16, 1977, 91 Stat. 1404; Pub. L. 101–549, title II, § 224, Nov. 15, 1990, 104 Stat. 2503; Pub. L. 102–240, title III, § 3004(b), Dec. 18, 1991, 105 Stat. 2088.)

Notes

Editorial Notes

Codification In subsec. (d), “August 7, 1977” substituted for “the date of enactment of this Act” to reflect the probable intent of Congress that such date of enactment meant the date of enactment of Pub. L. 95–95.

Amendments1990—Subsec. (e). Pub. L. 101–549 added subsec. (e). 1977—Subsec. (d). Pub. L. 95–190 substituted “December 31, 1980” for “December 31, 1981”.

Statutory Notes and Related Subsidiaries

Change of Name “Federal Transit Administration” substituted for “Urban Mass Transportation Administration” in subsec. (e)(2) pursuant to section 3004(b) of Pub. L. 102–240, set out as a note under section 107 of Title 49, Transportation.

Effective DateSection effective Aug. 7, 1977, except as otherwise expressly provided, see section 406(d) of Pub. L. 95–95, set out as an Effective Date of 1977 Amendment note under section 7401 of this title.