If there’s one thing you and your engine have in common, it’s that you both need clean air to function. This is why vehicles come with different air filters, namely engine air filters and cabin air filters. They might have similar names, but they’re two distinct parts that keep your engine and air conditioning (A/C) system functioning smoothly.
Most modern vehicles have two air filters: the engine air filter and the cabin air filter. Over 90% of new vehicles (2024) have cabin air filters. As for 2016 models, 70% of vehicles have them. Cabin air filters first appeared in Europe on the Saab 900 in 1979, but didn’t appear in any American car until Ford put them in the 1995 Ford Contour/Mercury Mystique models.
Cabin air filters and engine air filters both remove dust and other pollutants from the air that passes through the filter element.
The cabin air filter keeps particles as small as 0.1 to 0.3 microns from entering the passenger compartment when the A/C is set to “norm” rather than “max/recirc.”
The engine air filter prevents particles from 5 to 100 microns from entering the engine’s air intake system and interfering with your vehicle’s performance.
While people often mistake one for the other, engine air filters and cabin air filters are actually very different. Here are some of their differences:
The engine air filter is usually under the hood near the front, always near the fender inside the engine compartment.
Meanwhile, the cabin air filter is usually inside the passenger compartment behind the glove box or the dashboard on the driver’s side or in the center of the bulkhead mounted vertically, as on Nissan Altimas.
Teslas may have 2 cabin air filters, a large one across the rear of the front trunk (“frunk”) and another behind the glove box. Some Teslas just have one under the cowl like some of the more conventional vehicles and you always have to remove a plastic cover to access the filter no matter where it’s mounted.
For every gallon of fuel injected, the engine air filter has to clean the debris from 10,400 gallons of air. This is why engine air filters are large and have a round, conical, or flat shape. They’re specifically designed to clean millions of gallons of air.
On the other hand, cabin air filters are usually much smaller and flatter, similar to the filters used in home A/C units. They also have smaller surface pleats that can filter out pollen and other small particles.
In most vehicles, the engine air filter is easy to access, so most drivers can replace it themselves. All you have to do is open the engine air filter compartment in the engine bay, remove the dirty filter, and place a new one.
Unfortunately, a cabin air filter replacement can be a little more complicated than that, but it isn’t always, and sometimes cabin air filters come in two parts so that you have to remove one, then slide the other one over and remove it. GM Vans are set up this way and those are behind the glove box.
Aftermarket replacements for these will come as 2 smaller filters that you put through the hole one at a time. Because some cabin air filters are behind the glove box or under the dashboard, they can be hard to reach. You might need to hire a mechanic to change it for you.
The exact change interval will vary depending on your vehicle’s year, make, and model. However, most manufacturers recommend changing your engine air filter every 10,000 to 15,000 miles. As for cabin air filters, you usually have to replace them every 20,000 miles.
If you aren’t sure how often to replace your air filters, we recommend checking your owner’s manual. It should also contain information on where the filter is located and how to replace it.
Dirty air filters might not seem like a big deal, but they’ll start to show signs if you let them get too bad. Eventually they may get rotten, develop holes in the element, and then you’re driving with no air filter, slowly ruining the engine.
Here are the common effects of a dirty engine air filter:
When you take it out to check it (do this regularly) you should be able to see light through the filter element when you hold it up and look through it. Next, drop it and see if a bunch of dirt comes out of it. If it fails either test, replace it with a quality filter.
If you inspect your air filter regularly (and it’s very easy to do in most cases) you won’t need to look for symptoms. Some vehicles will have a “filter minder” device that will alert you if the pressure between the engine and the air filter indicates that the filter is restricted. If you drive a pickup, you may have one of these on your air cleaner. It’ll be clear plastic with a moveable/resettable indicator that will move into the red when the filter is restricted.
Other indicators of a dirty engine air filter include:
A dirty cabin filter will have different symptoms.
The exact price will vary depending on your vehicle’s year, make, and model, but you can expect engine air filters to cost anywhere from $10 to $1,110. Meanwhile, cabin air filters usually sell for $10 to $260.
Keep in mind that these prices only cover the cost of the product, so if you plan on hiring a mechanic to replace it for you, you’ll have to shell out more money.
Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.