Which CARB rules apply to my truck?

Most heavy-duty diesel vehicles with GVWR over 14,000 pounds operating in California fall under Clean Truck Check (HD I/M). Additional CARB programs—such as TRUCRS, Advanced Clean Fleets, and periodic smoke inspection rules for certain fleets—may also apply depending on vehicle type and operation. Confirm your obligations on arb.ca.gov.

Do CARB truck rules apply to out-of-state plates?

Yes, if the vehicle operates in California for commerce. Out-of-state registration does not exempt a qualifying heavy-duty diesel truck from Clean Truck Check when it travels on California roads.

Where are official CARB truck regulations published?

CARB publishes regulations, advisory documents, and program FAQs on arb.ca.gov. CTC-VIS at cleantruckcheck.arb.ca.gov is the operational portal for Clean Truck Check registration and testing status.

CARB truck regulations overview

California leads the nation in heavy-duty diesel emissions rules. For most truck owners and fleets, the highest-priority program today is Clean Truck Check—the state’s Heavy-Duty Inspection and Maintenance (HD I/M) system that requires periodic emissions testing and CTC-VIS registration.

Clean Truck Check at a glance

Clean Truck Check applies to most diesel trucks, tractors, and buses with a gross vehicle weight rating (GVWR) above 14,000 pounds that operate in California. Owners register each unit in the Clean Truck Check Vehicle Inspection System (CTC-VIS), pay CARB’s state compliance fee, and complete emissions testing within assigned due windows through a CARB credentialed tester.

Test methods depend on engine model year: OBD-based inspections are common on newer diesels, while smoke opacity testing applies to many older engines. Results are submitted electronically—compliance is not satisfied by a generic shop inspection or a passing pre-trip checklist alone.

Program requirements, fee amounts, and enforcement policies are defined in CARB regulations and updated through the rulemaking process. Always verify current rules on arb.ca.gov rather than relying on outdated forum posts.

How CARB truck rules fit together

Clean Truck Check is the operational compliance program most fleets interact with monthly. It sits alongside broader CARB diesel policies—engine standards at point of sale, fleet reporting under TRUCRS for certain operators, and long-term transition plans under Advanced Clean Fleets for some vehicle categories.

For day-to-day dispatch decisions, focus on three pillars: (1) Is the VIN registered in CTC-VIS? (2) Is the state compliance fee current? (3) Does CTC-VIS show a passing test within the open window? Missing any pillar can block DMV registration renewal or trigger roadside enforcement.

Practical compliance workflow

Register eligible units in CTC-VIS before or as soon as they enter California service. Pay the state compliance fee when prompted—CARB communications often reference an annual fee of $32.13 per vehicle, but confirm the current amount in your CTC-VIS account. Schedule testing early in your assigned window through a credentialed tester; Zurfex helps compare mobile and shop options by ZIP code.

After testing, verify that CTC-VIS reflects a passing status before dispatching the unit on revenue routes. If a vehicle fails, repair emissions-related faults and retest within CARB timelines. See our compliance checklist for a printable workflow.