Revision of Tier 4 Criteria Pollutant Standards, Part 1: Amendments to Phase-In Schedule for Light-Duty and Medium-Duty Vehicles
The comment period closed Jul 6, 2026.
The U.S. Environmental Protection Agency (EPA) is reconsidering the Tier 4 criteria pollutant standards for new motor vehicles promulgated within the final rule entitled "Multi-Pollutant Emissions Standards for Model Years 2027 and Later Light-Duty and Medium-Duty Vehicles." This reconsideration will occur in two separate, but coordinated, rulemakings. In this Part 1 rulemaking, the EPA is proposi
Summary from the Federal Register.
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Full history
- May 18, 2026
Rule published
Revision of Tier 4 Criteria Pollutant Standards, Part 1: Amendments to Phase-In Schedule for Light-Duty and Medium-Duty Vehicles
Environmental Protection Agency
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