What You Need to Know About Engine Air Filters

The engine air filter may look simple, but it's actually a quite important part for your engine. This guide covers everything you need to know about engine air filters.

What Does an Engine Air Filter Look Like?

Every Subaru model has its own engine air filter design. The most common design is a square or rectangular frame with filter material inside it that's folded in about 30 pleats. The filter material is designed specifically to handle the strong airflow coming into the engine while trapping dirt and debris.


Engine air filter

An engine air filter for select 1990-2008 Subaru models: part #16546AA020

Why Does Your Car Have an Engine Air Filter?

Basically, an engine air filter cleans the air going into the engine. The engine sucks in a lot of air because it needs oxygen for combustion. An air filter that's situated the engine's air intake is necessary to trap much dirt and debris because dirty air will damage the engine.

How Often Should You Replace the Engine Air Filter on a Subaru?

It's recommended to replace your engine air filter every 15 to 30k miles. However, it ultimately depends on several factors:

  • The size of the air filter: the bigger the air filter, the more dust and debris it's able to collect over time
  • The location of the air intake: some air intakes are located so that they take in less debris, such as bugs and leaves. This helps the air filter last longer than others that handle more debris.
  • The quality of the air outside: engine air filters in dusty and polluted areas don't last as long as the engine air filters in clean areas

What Happens if You Don't Replace Your Engine Air Filter?

Dirty subaru filter

Image Credit: Engineering Explained

The engine air filter is so important to your engine's health that neglecting to replace it will lead to many problems.

Generally, a dirty engine air filter will starve your engine of air. Modern fuel injected vehicle adjust for this, and reduce the amount of gas being fed into the air/fuel mixture. The engine will still run ok, but it won't have as much power. This will really be noticeable when accelerating.

A dirty engine air filter won't just deprive your engine of air and affect its performance. It may also let some dirt through. When the filter clogs, the engine can suck air past the seals at the edge of the filter. But this air won't be filtered, and can bring dust and dirt with it. Excessive dirt passing through the engine will prematurely wear engine components. In the short run, this can decrease performance and increase oil consumption. In the long run, the engine might need replacement much earlier than it should have.

There's really no excuse not to replace the engine air filter in your car. A replacement engine air filter is quite affordable (it's even more affordable if you order a genuine OEM one from us at wholesale pricing). Replacing the engine air filter in your car is a very easy and straightforward job that takes only a few minutes.

If you have any questions about the engine air filter in your Subaru, you're welcome to reach out to us.