California Truck Emissions & Clean-Truck Rules

How California handles truck emissions

This is the one state that tests your truck. Clean Truck Check (Cal. Health & Safety Code) covers nearly every diesel over 14,000 lb that drives in California, out-of-state plates included. Your fleet must register in CARB's system, pay the $32.13 annual fee per truck (2026), and pass periodic emissions tests, with deadlines set by your last VIN digit. CARB checks smoke at the roadside too. Non-compliance runs up to $10,000 per truck per day.

What applies to you

• Program: Clean Truck Check
• State rule: Clean Truck Check (HD I/M) applies to almost every non-gasoline vehicle over 14,000 lb GVWR that operates in California, out-of-state trucks included. The owner/fleet must register in CARB's CTC-VIS/TRUCRS system, pay a $32.13 annual compliance fee per vehicle (2026), and submit periodic passing OBD/opacity tests, up to twice a year for most non-agricultural vehicles, with out-of-state deadlines keyed to the last VIN digit. CARB also runs roadside and fixed-site smoke testing. California also adopted ACT (Title 13 CCR), a manufacturer sales mandate.
• Penalty: Non-compliance can block CA DMV registration and expose trucks to penalties advertised up to $10,000 per vehicle per day. Roadside smoke/opacity failures and tampering add more; federal anti-tampering penalties run about $45,000 per engine.
• DPF / DEF: Federal EPA equipment nationwide, never delete or tamper with it

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