Updated October 2026: The proposal described below became CARB’s Advanced Clean Fleets rule in 2023. After lawsuits and the loss of federal approval, its requirements for private, high-priority, and drayage fleets were repealed effective September 10, 2026. Only state and local government fleets are still covered. Diesel trucks are not being phased out for private owners under this rule.
What was proposed
In 2022 and early 2023, California’s Air Resources Board considered a proposal to phase out fossil-fueled medium and heavy-duty trucks by 2040 and push the industry toward electric trucks. Environmental groups wanted a faster transition by 2036, citing health concerns from diesel emissions. Trucking industry groups pushed back, warning about costs, unproven technology, missing charging infrastructure, and job losses.
The plan affected about 1.8 million trucks, with fleets owned by large companies converting gradually through 2042. Critics said it ignored the needs of many trucking operations, including high upfront costs and the small number of electric truck models available. The California Trucking Association pointed out that heavy batteries cut into payload and that the state would need a massive build-out of charging stations to meet demand.
What happened next
- 2023: CARB adopted the proposal as the Advanced Clean Fleets (ACF) rule, covering drayage trucks, government fleets, and large “high-priority” private fleets.
- 2024 and after: Truck equipment makers (NTEA and SEMA) sued in October 2024, and a coalition of 17 states brought its own lawsuit to block the rule.
- 2025: CARB withdrew its request for the federal waiver it needed to enforce the rule on private fleets, stopped enforcing the high-priority and drayage requirements, and agreed in settlements to repeal them. Its board voted for the repeal that fall.
- September 10, 2026: The repeal of the high-priority and drayage fleet requirements took effect. State and local government fleets remain covered, with extended deadlines.
What it means today
For private fleets and owner-operators in San Diego, there is no longer a state mandate to replace diesel trucks with zero-emission models. Diesel trucks still have to meet California’s emissions rules, though. The Clean Truck Check program requires most heavy-duty trucks to pass emissions testing twice a year, moving to four times a year for most newer trucks in October 2027. Keeping your diesel truck’s emissions system in good shape is now the main compliance job.
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Need commercial truck repair or a Clean Truck Check in San Diego? Kearny Mesa Truck Center has kept San Diego trucks on the road since 1970. Open Monday to Friday, 8am to 5pm, at 5624 Kearny Villa Rd.