When it comes to preparing a car for registration, it’s easy to lump in smog checks with all the other steps. But you’d be wrong to think that a smog check isn’t more important than a trip to the DMV. Certain factors make this service a top priority.

The California Smog Check Program requires vehicles manufactured in 1976 or later to get a smog check every two years. With only a few exceptions, gas-powered cars, hybrid cars, and alternative-fuel vehicles that are eight model-years old or newer are not required to participate.

If you think San Diego smog is bad just look at Beijing pollution issues.