On March 29, 2024, EPA finalized the Phase 3 greenhouse gas standards for heavy-duty vehicles — the strongest federal emissions standards to date for trucks and buses, phasing in through model year 2032. In July 2026, EPA Administrator Lee Zeldin announced a proposal to weaken these standards, calling them “unnecessary and unworkable.”
This is part of a broader pattern of deregulatory action this year, including the repeal of the scientific “Endangerment Finding” that has served as the legal foundation for federal vehicle emissions regulation, the elimination of federal tailpipe standards for passenger cars and trucks, and the revocation of California’s Clean Air Act waiver authority via Congressional Review Act resolutions.
There are a couple of ways you can take action:
- Submit a written comment here or at regulations.gov by 11:59pm ET on August 29, 2026.
- Raise awareness by sharing this toolkit with 5 colleagues and encouraging them to take action.
