California Diesel Smog Rules (with Pictures)

The California State Air Resource Board admits to having the most polluted air in the nation. Because of that, the Golden State has some of America's strictest smog regulations, requiring drivers to get a biennial smog check and imposing tough regulations on big-rig owners. But there are some exceptions of which diesel owners should be aware.

Who Gets A Smog Check?

According to California law, not all vehicles must get a smog check. Diesel vehicles manufactured prior to 1998 or with a gross vehicle weight (GVW) of more than 14,000 pounds are exempt from the biennial smog check. Also, if your vehicle is six or fewer model years old, instead of a smog check, the state will tack on a smog abatement fee to your annual registration. Additionally, only certain counties in California are subject to the biennial smog check.

Not all vehicles are required to get a smog check.
What Happens If You Fail the Smog Check?

A law went into effect on January 1, 2009, that limits your ability to get an extension on your vehicle's registration renewal if you fail a smog test. The law only allows people who failed a smog test to get a temporary operating permit. If you are in that group and your registration is due, you still must pay your registration fees plus $50 for one 60-day temporary operating permit. The old law allowed you to get a temporary operating permit if for any reason you could not get a smog certificate.

A new law limits your ability to get an extension on your vehicles registration renewal.
Diesel Trucks and Big Rigs

Vehicles in California with a GVW of more than 14,000 pounds are not subject to the biennial smog check. But, according to the environmental protection group ForceChange, they still operate under some of the toughest standards in the nation. In December of 2008, the California Air Resources board passed strict rules to clean-up big-rig pollution. Starting on January 1, 2011, truck owners will have to install diesel exhaust filters on their rigs. And beginning in 2012, owners will have to replace engines older than the 2010 model year on a staggered schedule through 2022.

Vehicles in California with a GVW of more than 14,000 pounds are not subject to the biennial smog check.