Trump signs law ending California’s emissions authority and EV mandate while restoring federal control over vehicle standards

On June 12, 2025, President Trump signed three Congressional Review Act resolutions into law that formally revoked California’s authority to enforce its own vehicle emissions standards. The move blocks the state’s 2035 ban on new gas-powered vehicles and nullifies its stricter tailpipe and diesel truck emissions rules. The signing reestablishes federal supremacy over vehicle regulations and marks a major shift in national environmental policy.

The resolutions were passed by Congress in May 2025 and target California’s long-standing waivers under the Clean Air Act. These waivers had allowed the state to set tougher emissions standards than the federal government. California, which accounts for roughly 11% of the U.S. auto market, has historically influenced national trends through its regulatory power. That authority is now rescinded.

The new law also cancels California’s rules phasing out medium and heavy-duty diesel vehicles and its nitrogen oxide limits for trucks. These measures were part of the California Air Resources Board’s broader climate agenda. With the federal government now overriding those policies, CARB’s regulatory reach is significantly reduced.

President Trump signed the resolutions during a White House ceremony, calling the move a win for consumer choice and energy independence. He also referenced his “Big Beautiful Bill,” which eliminates federal incentives for electric vehicles and redirects funding toward domestic oil and gas production.

The Environmental Protection Agency under Administrator Lee Zeldin supported the rollback, stating that it would remove billions in compliance costs and restore a single national standard. The Department of Transportation and Department of Energy were also present at the signing, signaling full executive alignment behind the policy.

California Governor Gavin Newsom immediately announced a legal challenge. The state’s attorney general filed suit within hours, joined by ten other states. They argue that the Congressional Review Act cannot be used to revoke California’s Clean Air Act waivers. The legal outcome remains uncertain, but the federal law is now in effect.

As of June 2025, California’s smog check program and CARB enforcement mechanisms remain operational. However, without federal recognition, their authority to impose stricter standards is limited. No legislation has yet passed to defund CARB, but budget proposals circulating in Congress suggest that funding could be cut by January 2026.

For diesel vehicle owners, this means federal standards now apply nationwide. State-level exemptions and aftermarket restrictions are no longer enforceable under the new law. However, until CARB is formally defunded or dissolved, some state-level testing and compliance requirements may still be enforced during the legal transition.