The Difference Between “Basic” and “Enhanced” Area Smog Testing

For most California motorists, the required biennial smog check is a routine process that usually ends up going fairly smooth unless their vehicle fails the test and needs repairs.

However, there is another stumbling block that a handful of vehicle owners may experience as well.

Occasionally, while out of town on vacation, or away from home on business, one may decide to take advantage of his or her free time and go find a local auto shop to take care of that smog test that’s been on the back burner for the last few weeks.

In many cases, there won’t be any problems.  On the other hand for example, if you are looking for a smog check in Santa Maria, which is classified as a “basic” area, and the vehicle to be tested is registered in a county that is classified as an “enhanced” area, the smog test will need to be performed using a special machine called a dynamometer or “Dyno” for short.

Dyno-Testing” used in the enhanced smog check produces a more accurate smog profile of your car because it measures it’s exhaust output under simulated driving conditions by testing it while it runs on an automotive treadmill.

This type of machine is required for smog checks that take place in large population areas where emissions levels are much higher like Los Angeles, Riverside, Bakersfield, etc.  If you have never lived in an area where smog tests using a dynamometer were required, here’s an idea of what the test looks like:


If you currently live in an enhanced area but are planning to move to a basic area, you should visit the DMV and update your information prior to having a smog check performed on your vehicle.

Coming soon:  A new and quicker version of the California smog check for vehicle model years 2000 and newer.