What Year Trucks Are Allowed in California: 2010 Engine Rule

If you run a diesel truck over 14,000 pounds gross vehicle weight rating, the rule for what year trucks are allowed in California is straightforward: the engine must be model year 2010 or newer. The requirement has been in full effect since January 1, 2023, and it applies to every diesel truck on California roads, whether it is registered in the state or just passing through.¹

The 2010 Engine Rule

The requirement lives in California’s Truck and Bus Regulation, Title 13, Section 2025 of the California Code of Regulations. Any diesel, dual-fuel, or alternative-diesel vehicle with a GVWR above 14,000 pounds must run a 2010 model year engine or an emissions-equivalent setup to operate legally in the state.² The net is wide. It covers privately owned trucks, federally owned trucks, school buses, yard trucks with on-road engines, and two-engine sweepers.

Gasoline-powered trucks over 14,000 pounds are not covered. The rule targets diesel emissions, so a gas truck above the weight threshold is outside the 2010 engine mandate entirely. Trucks that run exclusively on non-diesel alternative fuels fall outside it as well.

Out-of-State Trucks Are Not Exempt

This catches many operators by surprise. The regulation applies to every diesel truck operating in California, not just California-registered ones. A truck based in Texas, Ohio, or anywhere else has to meet the same 2010 standard the moment it crosses the state line.¹ CARB offers no exemption based on where the truck is registered.

Narrow Exemptions That May Apply

A handful of exemptions can keep an older truck legal in specific situations. None are automatic. Most require you to report through CARB’s online system, TRUCRS (Truck Regulation Upload, Compliance, and Reporting System), before you operate.

Low-use vehicles. Trucks that travel fewer than 1,000 miles per calendar year within California can qualify. You report odometer readings in TRUCRS at the start of the year and again at year-end to prove the in-state mileage stayed under the threshold. A truck that drives 50,000 miles a year nationally can still qualify so long as fewer than 1,000 of those miles happen in California.³⁴
Three-day pass. A non-compliant truck entering California can request a temporary three-day operating permit, limited to one vehicle per calendar year. The request must be submitted before the truck enters the state, and online filings can be approved instantly.⁵
Private-use motorhomes. Motorhomes used for non-commercial personal purposes are exempt from the Truck and Bus Regulation.²
Personal-use pickup trucks. Pickups with a GVWR of 19,500 pounds or less that have a pickup bed and are used exclusively for personal, non-commercial purposes are exempt. Use the truck for any commercial or government purpose and the exemption disappears.⁶

The personal-use exemptions hinge on how you actually use the vehicle. A diesel pickup hauling personal camping gear is exempt. The same truck hauling materials for your landscaping business is not.

Drayage Trucks Face a Tougher Standard

If your truck is a drayage truck moving cargo between California seaports, intermodal railyards, and nearby distribution points, the 2010 engine rule is not the ceiling. Under the Advanced Clean Fleets regulation, any new drayage truck registered in CARB’s online system since January 1, 2024 must be a zero-emission vehicle. By 2035, every drayage truck operating in California must be zero-emission.⁷

These rules generally reach Class 7 and Class 8 trucks with a GVWR above 26,000 pounds hauling containerized, bulk, or break-bulk cargo to and from ports and railyards.⁸ Recent amendments to the Advanced Clean Fleets regulation could repeal portions that apply to federal and private fleets, including some drayage requirements, and those amendments are expected to take effect before January 2027.⁹ Drayage operators should watch CARB advisories closely while the rules shift.

What Happens If the Truck Isn’t Compliant

Enforcement works through several channels at once. The California DMV refuses to renew registration on non-compliant California-plated trucks, so a pre-2010 engine effectively grounds the vehicle in-state.¹ For out-of-state trucks, CARB uses roadside emissions monitoring devices and automated license plate readers to flag suspect vehicles, so getting caught does not require a traffic stop.¹⁰

The money side is serious. Administrative penalties for violating the Truck and Bus Regulation run from $100 to $25,000 per vehicle.¹¹ A violation of California’s air pollution regulations is also a misdemeanor punishable by a fine of up to $5,000, up to six months in county jail, or both, and each day the violation continues counts as a separate offense.¹² Out-of-state brokers and dispatchers have been fined for sending non-compliant trucks into California, so liability does not sit only with the truck owner.

Bringing an Older Truck Into Compliance

If your engine is pre-2010, the cleanest fix is a repower with a 2010 or newer engine that meets current nitrogen oxide and particulate matter standards. Engine repowers are common in the heavy-duty market, and several manufacturers produce compliant replacement engines for popular truck platforms.

In earlier phases of the regulation, bolting a CARB-verified diesel particulate filter onto an older engine was enough. That no longer works for most trucks. The current standard asks for a 2010 engine or an emissions-equivalent setup, meaning the older engine must also achieve specific nitrogen oxide reductions, not just particulate matter reduction.² A particulate filter alone on a pre-2007 engine will not get you there. For most owners of older trucks, the practical choice is an engine swap or a newer truck.

Compliance Doesn’t End at the Engine Year

Meeting the 2010 engine rule gets you on the road. It does not end your obligations. Non-gasoline vehicles over 14,000 pounds GVWR also fall under California’s Clean Truck Check program, which charges an annual compliance fee and requires periodic emissions testing. The 2026 fee is $32.13 per vehicle, adjusted from $31.18 using the California Consumer Price Index.¹³ Most heavy-duty trucks test twice a year. California-registered motorhomes used for personal recreation and agricultural vehicles test once a year, and zero-emission vehicles are exempt from testing entirely.¹⁰ Factor those recurring costs in when you weigh keeping an older compliant truck against moving to a newer one.

1
California Air Resources Board. Truck and Bus Regulation
2
Legal Information Institute. California Code of Regulations Title 13, 2025 – Regulation to Reduce Emissions of Diesel Particulate Matter, Oxides of Nitrogen and Other Criteria Pollutants, from In-Use Heavy-Duty Diesel-Fueled Vehicles
3
California Air Resources Board. Truck and Bus Flexibility Options – Section: Low-Use Exemption
4
California Air Resources Board. Truck and Bus Regulation Low-Use Vehicle Exemption FAQ
5
California Air Resources Board. Emergency Use Exemption (Truck and Bus Regulation)
6
California Air Resources Board. Truck and Bus Regulation Basics and Exemptions
7
Legal Information Institute. California Code of Regulations Title 13, 2014.1 – In-Use On-Road Heavy-Duty Drayage Trucks Requirements and Compliance Deadlines
8
California Air Resources Board. Advanced Clean Fleets Regulation Drayage Truck Requirements Factsheet
9
California Air Resources Board. Zero-Emission Regulation Deadline Schedules
10
California Air Resources Board. Clean Truck Check (HD I/M)
11
California Air Resources Board. 2014-2024 Minimum and Maximum Penalties
12
California Legislative Information. California Health and Safety Code 42400
13
California Air Resources Board. Clean Truck Check Compliance Fee Update Effective 1/1/2026