In a recent legal clash, four major truck manufacturers, including Daimler and Volvo, have filed a lawsuit against the state of California. This legal action is aimed at preventing California from enforcing certain emissions standards that had been nullified by the Trump Administration. This lawsuit highlights the ongoing struggle between federal and state jurisdictions over environmental regulations, a battle that intensifies the uncertainties faced by Original Equipment Manufacturers (OEMs) trying to navigate these conflicting mandates.
The manufacturers are challenging California’s regulations by requesting a declaratory judgment from the US Court for the Eastern District of California. They argue that the Clean Truck Partnership (CTP) and a corresponding Manufacturers Advisory Correspondence are “underground regulations” contrary to the California Government Code § 11340.5(a). The suit also asserts that enforcing state vehicle emissions standards without an Environmental Protection Agency (EPA) waiver of preemption infringes upon federal law. Caught between California’s aggressive regulatory stance and federal orders to disregard these requirements, the manufacturers claim they are being placed in an untenable position.
Notably, the CTP calls for truck manufacturers to align with California’s ambitious vehicle emission standards and embrace zero-emission technologies, despite potential conflicts with federal mandates. While this agreement offers the manufacturers certain flexibilities, it still exposes them to legal uncertainties. The Biden Administration did grant California a waiver under the federal Clean Air Act (CAA) to set its own standards, recognizing the state’s unique environmental challenges. However, subsequent legislative measures, such as the Stop California from Advancing Regulatory Burden Act of 2025, signed into law by former President Trump, have repealed the relevant CAA section, complicating the legal landscape.
Former President Trump’s rhetoric when signing the Act underscored a federal agenda to curb California’s regulatory ambitions, claiming it would rescue the U.S. auto industry. California leaders have been vocal in their opposition, with Governor Gavin Newsom condemning these federal measures as detrimental to both environmental progress and economic competitiveness.
Despite the legal contention, California has not backed down. In June, the state joined forces with ten other states to challenge the Congressional Review Act in federal court. While awaiting the court’s decision, California continues to uphold its regulatory expectations under the CTP. In turn, this has led to further federal pushback, including a cease-and-desist letter from the acting Assistant Attorney General of the Environment and Natural Resources Division of the U.S. Department of Justice, demanding OEMs to halt compliance with the CTP.
This ongoing legal tug-of-war underscores a broader national discourse on state versus federal rights in environmental policy. The outcome will likely have significant implications for the regulatory landscape automotive manufacturers must navigate. For more detailed insights, read more.