Overview

• The Justice Department and EPA filed two federal complaints with motions to intervene in the Eastern District of California and Northern District of Illinois to enjoin enforcement of preempted truck emissions standards.
• Four major manufacturers—Daimler Truck North America, Volvo Group North America, PACCAR and International Motors—sued California seeking a declaratory judgment and injunction against its Clean Truck Partnership obligations.
• Congress and President Trump voided EPA preemption waivers for California’s heavy-duty truck rules under the Congressional Review Act in June 2025, nullifying the state’s legal basis for stricter emissions standards.
• The Clean Truck Partnership, intended to give manufacturers certainty on zero-emission targets, has become central to debates over whether state-level agreements can replace formal EPA waiver authority.
• With parallel suits, pending appeals and competing motions, courts have yet to resolve the overlapping litigation or provide regulatory clarity for fleets and OEMs.