National Association of Clean Air Agencies
EPARulemakingEPA-HQ-OAR-2025-3297

Revision of Tier 4 Phase-in Schedule for Light-Duty and Medium-Duty Vehicles

RIN
2060-AW96
Last modified
Jul 1, 2026
Comment window
closed 22d ago
National Association of Clean Air Agencies filings
1

Activity

National Association of Clean Air Agencies filed 1 comment on this docket between Jul 1, 2026 and Jul 1, 2026. 34 other organizations filed here. The comment window closed 22d ago.

What National Association of Clean Air Agencies filed (1)

Jul 1, 2026· Comment submitted by National Association of Clean Air Agencies (NACAA)· EPA-HQ-OAR-2025-3297-0116

Filed on regulations.gov — full text not in the inline record.

Abstract

The U.S. Environmental Protection Agency (EPA) is proposing to extend the Tier 3 criteria pollutant standards for vehicles up to 6,000 pounds gross vehicle weight rating into model years (MYs) 2027 and 2028, and to delay the start of the phase-in of the Tier 4 criteria pollutant standards until MY 2029.

View on regulations.gov →