Engine Air Filter vs. Cabin Air Filter: Key Differences Explained

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.

How Many Air Filters Does a Car Have?

Most modern vehicles have two air filters: the engine air filter and the cabin air filter.

They both prevent dust and other pollutants from entering the air intake system and interfering with your vehicle’s performance. The difference is that engine air filters specifically keep debris from entering the engine, while the cabin air filter prevents contaminants from entering the cabin.

Air Filter vs Cabin Air Filter: What Are the Differences?

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:

Location

While its exact location can vary depending on your vehicle’s year, make, and model, the engine air filter is usually under the hood near the front. In some vehicles, it’s located 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. Some vehicles also have the cabin air filter hidden in the windshield cowl under the hood, where you have to remove a plastic cover to access it.

Size and Shape

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.

Ease of Replacement

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. 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.

How Often Should Air Filters Be Changed?

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.

What Happens if You Don’t Change Your Air Filters?

Dirty air filters might not seem like a big deal, but they’ll start to show signs if you let them get too bad. Here are the common effects of a dirty engine air filter:

Signs of a Dirty Engine Air Filter

• Poor Fuel Economy – A clogged air filter will prevent air from reaching the engine, forcing the engine to use more fuel than it normally would.
• Reduced Power and Acceleration – Without receiving enough air, the engine won’t be able to produce enough horsepower, causing the acceleration to feel sluggish.
• Engine Misfires – When there’s too much fuel and not enough air, the engine is likely to misfire and have trouble starting.
• Illuminated Check Engine Light – A clogged engine air filter will prevent the engine from operating properly, which will eventually trigger the check engine light.

A dirty cabin filter will have different symptoms.

Signs of a Dirty Cabin Air Filter

• Poor A/C and Heating Performance – Dirty cabin air filters will block airflow, causing the heating, ventilation, and air conditioning (HVAC) system to malfunction.
• Bad Smell – The dirty odor you smell from the vents is usually caused by bacteria or mold growing on the clogged air filter.
• Decreased Defrosting Capacity – Without enough air flowing through the vents, the heater won’t be able to effectively defrost your windows.
• Fan Noises – A clogged air filter will most likely fail to block debris from entering the A/C system, leading to large particles getting stuck in the blower motor. When the blower motor turns on, these large particles can hit it and make loud noises.

How Much Does an Air Filter & Cabin Air Filter Replacement Cost?

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.