On August 12, 2025, the Federal Trade Commission (FTC) announced it had closed its investigation into possible antitrust violations by four truck manufacturers and their trade association by entering into the Clean Truck Partnership agreement with the California Air Resources Board (“CARB”). In separate letters delivered to the FTC, each manufacturer and the Engine Manufacturers Association acknowledged the Clean Truck Partnership is unenforceable; committed to act independently in selling heavy-duty trucks; and promised not to enter any agreement with a U.S. state regulator committing to comply with regulatory limits a state has no authority to impose.
The FTC’s announcement came one day after the same truck manufacturers filed a federal lawsuit in California seeking to void the Clean Truck Partnership, citing recent congressional action preempting California’s emissions standards for heavy duty trucks; CARB’s demand that the OEMs nevertheless honor their commitment to comply with California regulation; and letters from the U.S. Department of Justice (DOJ) directing the manufacturers to cease and desist complying with the preempted state mandates. Complaining they are “caught in the crossfire,” the OEMs warned in their complaint: “This situation is not tenable.”
FTC Antitrust Concerns With Clean Truck Partnership
Between 2021 and 2023, CARB issued a series of emissions standards for heavy duty trucks sold in California that were significantly more stringent than federal requirements under the Clean Air Act. Facing increasing regulatory uncertainty and without adequate lead time to develop compliant products, four heavy duty truck manufacturers worked with their trade association to negotiate the Clean Truck Partnership with CARB. Under the terms of that July 2023 agreement, CARB modified its emission requirements and the heavy duty manufacturers promised they would comply with CARB’s requirements—including the requirement that they would exclusively sell zero-emission vehicles in California beginning by model year 2036—“irrespective of the outcome of any litigation challenging” the California standards.
In its August 12 closing statement, the FTC said the antitrust concerns with the Clean Truck Partnership were “obvious” and warned that U.S. antitrust laws “take the dimmest possible view of agreements among competitors to restrict output or otherwise to cease competing.” The FTC argued the agreement was beyond the protection of either the state action doctrine or the Noerr-Pennington doctrine. First, a group of competitors “controlling essentially all of a market” had entered into an “agreement” with a state agency to adopt output limitations, as opposed to petitioning that agency to adopt a rule imposing those limitations on market participants. Second, and more troubling to the FTC, the so-called “Dead Hand Provision” in the Clean Truck Partnership agreement committed participating truck manufacturers to comply with these output reductions even if CARB ultimately were found to lack authority to implement them.
Truck Manufacturers Seek Relief from Clean Truck Partnership
The day before the FTC announced it had closed its investigation, the four truck manufacturers filed suit against CARB and California governor Gavin Newsom in federal court in California seeking to enjoin preliminarily and permanently enforcement of the Clean Truck Partnership. In that lawsuit, the manufacturers allege that, notwithstanding congressional action in June 2025 invalidating preemption waivers granted by the Environmental Protection Agency (EPA) during the Biden Administration, CARB continues to press manufacturers to comply with California emissions standard for heavy duty trucks, invoking the Clean Truck Partnership as a basis for doing so. The manufacturers argue that CARB cannot invoke that agreement, both because CARB has amended California emissions requirements in ways that undermine the rationale for the arrangement in the first place, and because changes to the regulatory landscape are not the product of “litigation,” but rather congressional action preempting the California regulations altogether.
The DOJ on August 14, 2025 moved to intervene in the lawsuit filed by the heavy duty truck manufacturers, arguing the federal government has “a legally protectable interest to set and enforce national uniform standards for vehicular emissions, as mandated by Congress in its determination of the public interest.” Meanwhile, a challenge to the recent congressional action revoking the Biden-era EPA preemption waiver for California emissions standard for passenger cars is proceeding in a parallel lawsuit filed in federal court by the State of California and ten other states that have adopted California’s zero-emission vehicle (ZEV) regulations under Section 177 of the Clean Air Act (CAS 177). An initial case management conference is scheduled for September 16, 2025, but the states have not sought preliminary injunctive relief in that action.
