Air filter vs cabin air filter car

Your car uses all different kinds of filters to keep contaminants out of vital systems. Specifically, filters are used on things that flow — air and fluid (think oil and fuel) — but did you know there are actually two types of air filters in your car? How much do you know about engine air filters vs. cabin filters and the important role each plays?

Engine Air Filters

These air filters can be round, conical or panel-shaped, depending on the vehicle. They’re located under the hood, generally near the front of the engine, and are covered by housing. There must be some opening in the housing wide enough for the engine to suck up large volumes of air. However, if the filter were completely exposed, it would quickly become clogged and dirty and unable to do its job.

And what exactly is that job? It keeps debris and even particles as small as dust out of the engine intake. Engines work in very tight clearances, at very rapid speeds, under very hot temperatures, and even a small amount of dirt can wear down major components and cause catastrophic damage. The filter will eventually clog and need to be cleaned or changed. A clogged engine air filter causes reduced performance, increased emissions and increased fuel consumption.

Cabin Air Filters

These guys are usually panel-shaped and live in their own housing under the dash, often on the passenger side. Instead of protecting your engine, they play the important role of protecting you. These filters are positioned between the outside elements/engine compartment and your passenger cabin. Aside from debris (which you’ll notice more of if you drive a lot on back roads), they catch mold spores, engine exhaust fumes and allergens. Although they won’t affect your engine performance, they will definitely affect your quality of ride. Failing to change an old or clogged cabin air filter can result in musty smells, sneezy riders and literal headaches.

A Change Will Do You Good

Both filters are pretty accessible, with the engine air filter probably being the easier of the two. On some vehicles, you don’t even need tools to get to it, just undo some latches and voila — access! Your owner’s manual will specify the correct procedure, so check there first. To replace cabin air filters, you might have to work a little harder, sticking your head under the dash and removing a few small bolts. It isn’t difficult, though, and again — your owner’s manual should be able to walk you through it.

Checking both filters should be a part of any annual tune-up. If you’re experiencing one of the symptoms mentioned above, make sure to change them out. If you spend a lot of time in dusty or dirty conditions, they’ll have to be changed or cleaned more often than your owner’s manual specifies, so don’t just rely on the numbers. As easily accessible as they are, there isn’t really a good excuse to not keep ’em clean. Here’s how to change an engine air filter:

Check out all the filters available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on engine air filters vs. cabin filters, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

Photos courtesy of Blair Lampe.

Blair Lampe View All

Blair Lampe is a New York-based professional mechanic, blogger, theater technician, and speechwriter.  In her downtime she enjoys backpacking wherever her boots will carry her, rock climbing, experimental theatre, a crisp rosé , and showering love on her 2001 Sierra truck.