Which vehicles need Clean Truck Check? A truck-type guide

Short answer: Clean Truck Check covers most diesel and alternative-fuel vehicles over 14,000 lb GVWR that operate in California. That includes semis, box trucks, dump trucks, tow trucks, buses and many motorhomes, whether they are registered in California, another state or another country. Your engine model year decides which test you need, not the body style.

Which vehicles need Clean Truck Check?

The rule is built on two things: weight and fuel. If a vehicle runs on diesel or an alternative fuel, is rated over 14,000 lb gross vehicle weight (GVWR) and operates in California, it is most likely covered.

Body type does not change that. A Class 8 sleeper and a Class 6 delivery truck are in the same program if both are over the weight line. That is why the question "does my truck need it?" almost always comes down to the GVWR on the door label and the fuel the engine burns.

Covered vehicles also include trucks that live outside the state. Out-of-state and international trucks that drive in California are part of the program. See Clean Truck Check for out-of-state trucks for more.

Truck types we test most often

Here is how common vehicle types line up. In every case the 14,000 lb GVWR rating and the fuel type are what count.

Semis and tractors

Semi truck emissions tests in California are the bulk of the program. Day cabs, sleepers, heavy haul tractors, car haulers, tankers and reefer trucks are all over 14,000 lb GVWR, so they are covered when they run in California.

Box trucks, step vans and delivery trucks

Many box trucks need a Clean Truck Check, but not all. A large box truck or reefer used for delivery is usually rated over 14,000 lb. Smaller step vans and cab-overs, such as some Isuzu NPR and Hino models, can fall on either side of the line depending on the build. Check the GVWR on the door label before you decide.

Dump trucks, roll-offs and construction trucks

Dump trucks, roll-off trucks, concrete mixers, water trucks, crane trucks and bucket trucks are almost always heavy enough to be covered. Construction fleets are part of the program, and we test at jobsites as well as yards.

Tow trucks and flatbeds

Heavy tow trucks and wreckers are covered. Light-duty tow trucks and flatbeds built on smaller chassis may be under 14,000 lb, so the door label decides.

Garbage trucks and street sweepers

Refuse trucks, garbage trucks and roll-off haulers are covered. Street sweepers and other special vehicles can have their own rules, so check CARB's rules for your vehicle before you assume either way.

Buses

School buses, transit buses, coach buses and larger shuttle buses over 14,000 lb are part of the program. Smaller shuttles built on light chassis may be under the line.

Medium-duty chassis: F-450, F-550, F-650, Ram 4500/5500, Silverado 6500

These are the trucks people ask about most. A Ford F-650 or Silverado 6500 is usually rated well over 14,000 lb. A Ford F-450, F-550, Ram 4500 or Ram 5500 may be just over or under the line depending on the configuration. The rating on your own door label settles it. Our pickup guide covers this in more detail.

Motorhomes

Diesel motorhomes over 14,000 lb GVWR can fall under the program. See Clean Truck Check for motorhomes.

Agricultural and livestock trucks

Agricultural trucks, hay trucks and livestock trucks over 14,000 lb are included in the program where they fall under it. CARB has specific rules for some farm vehicles, so check CARB's rules or our exemptions guide before assuming yours is exempt.

Fire trucks and other special cases

Emergency vehicles, military vehicles and other special categories have their own treatment under CARB's rules. We don't guess on these. Check CARB's rules for your vehicle or look it up in CTC-VIS.

Which test does each vehicle need?

The test depends on engine type and model year, not on whether it is a bus, a dump truck or a semi.

• 2013 and newer diesel engines: CARB-verified OBD test. See OBD testing.
• 2012 and older diesel engines without OBD: smoke opacity test plus a visual inspection. See smoke opacity testing.
• 2018 and newer alternative-fuel engines: CARB-verified OBD test.
• 2017 and older alternative-fuel engines without OBD: visual inspection.

So a 2015 dump truck and a 2015 sleeper get the same OBD test, while a 2010 box truck gets a smoke test and visual inspection.

How to check if your vehicle needs Clean Truck Check

1. Find the GVWR. It is printed on the label on the driver's door or door jamb. If it reads over 14,000 lb, keep going.
2. Confirm the fuel. Diesel and alternative-fuel engines are covered.
3. Ask if it runs in California. Registration state does not matter. Operating in California does.
4. Look it up in CTC-VIS. CARB's CTC-VIS system is where owners report vehicles, pay the annual compliance fee and see deadlines. Our CTC-VIS registration guide walks through it.
5. Check edge cases with CARB. If you think your vehicle might be exempt, confirm it with CARB's rules before you skip a test.

Most covered vehicles currently test twice a year. Missing a deadline can lead to a DMV registration hold for California-registered vehicles, plus CARB citations and penalties.

How Diesel Dynamix helps

Diesel Dynamix is an independent mobile testing service in Southern California. We are not CARB. We come to your yard, jobsite, terminal, port or home and run the right test for each vehicle, whether it is one tow truck or a mixed fleet of semis, buses and dump trucks.

• We explain results in plain English and give you the next due date.
• We help with CTC-VIS questions.
• Fleets get per-truck pricing, recurring visits, early-morning visits, reminders and records per VIN. See fleet testing.

We cover Los Angeles, Long Beach, Orange County, the Inland Empire, San Diego and El Centro. See our service areas, then book a test or call or text (858) 342-8328.