California and major truck companies clash in clean emissions lawsuit
AI-generated summary reviewed by our newsroom.
- Four truckmakers sued California over Clean Truck Partnership enforcement.
- CARB filed a countersuit claiming manufacturers breached 2023 emissions commitments.
- Environmental groups warned the legal fight will raise pollution and harm public health.
A judge in Sacramento federal court will hear a lawsuit Friday from four major truckmakers challenging California’s authority to enforce its Clean Truck Partnership, which commits them to cut pollution from heavy-duty vehicles and back the state’s zero-emission goals.
The companies, Daimler Truck North America, Volvo North America, International Motors and PACCAR, sued the state in August, arguing that California can no longer enforce the agreement after the Trump administration used the Congressional Review Act earlier this year to rescind the federal waivers that allowed the state to set its own clean-truck standards.
As that case moves forward, meanwhile, the California Air Resources Board this week filed suit against the same manufacturers, arguing they broke the agreement that explicitly committed them to follow California’s standards even if the state’s authority came under challenge.
“In exchange for more flexible options to comply with California emissions regulations, they would continue to produce cleaner engines no matter what attacks on California regulations might come,” the board chair, Lauren Sanchez, said in a statement Tuesday.
“CARB and several other manufacturers have upheld their end of the deal, but these four manufacturers have reneged on theirs.”
The Clean Truck Partnership is a 2023 agreement between California regulators and major truck manufacturers to comply with a broad state effort to phase out diesel pollution and transition toward zero-emission technology. CARB argues that the manufacturers are still bound by the commitments they made under the partnership, which explicitly require them to meet California’s standards even if the state’s authority to enforce those rules is challenged.
“The Clean Truck Partnership…marks a commitment from the companies to meet California’s vehicle standards that will require the sale and adoption of zero-emissions technology in the state, regardless of whether any other entity challenges California’s authority to set more stringent emissions standards under the federal Clean Air Act.” the statement from 2023 announcing the agreement read.
Environmental groups, including the Sierra Club, condemned the manufacturers’ lawsuit against California, stating the companies’ “U-turn away” from their clean-truck commitments is “unacceptable.”
”Retreating from the established commitments will increase pollution for communities, worsen public health threats and stall American competitiveness,” Sierra Club Clean Transportation for All Director Katherine García said in a statement Wednesday.
“The Clean Truck Partnership isn’t just a manufacturing agreement with the state of California — it’s a commitment to truck drivers, fleets and communities eager to reap the economic and health benefits from electric trucks.”
This story was originally published October 30, 2025 at 2:00 PM with the headline "California and major truck companies clash in clean emissions lawsuit."
