Engine Air Filter vs Cabin Air Filter
Reviewed by GarageDex editorial
They sound alike but do different jobs. The engine air filter cleans the air the engine burns and lives in the airbox under the hood. The cabin air filter cleans the air that comes through your vents and usually sits behind the glovebox. Your car has both, they use different parts, and they have different replacement intervals.
The key differences at a glance:
| Engine air filter | Cabin air filter | |
|---|---|---|
| What it cleans | Air going into the engine | Air going into the cabin |
| Location | Airbox under the hood | Usually behind the glovebox |
| Replace every | ~30,000 mi | 15,000-20,000 mi |
| Symptom when dirty | Lower mpg/power | Weak airflow, musty smell |
Don't confuse them when buying
Because they are different parts, you need the correct number for each. Look up both filter part numbers for your car, and see how to change each one.
Frequently asked
Are the engine and cabin air filter the same?
No. They are separate parts in different locations with different part numbers. The engine air filter protects the engine; the cabin air filter cleans the air you breathe. Both need periodic replacement.
Which one affects gas mileage?
The engine air filter. A clogged engine filter restricts airflow to the engine and can hurt performance and efficiency. The cabin filter only affects airflow and air quality inside the car.
Can I replace both myself?
Yes - both are quick, no-tool jobs on most cars. The engine filter is in the airbox under the hood; the cabin filter is behind the glovebox. See our how-to guide.
Need your car's exact spec? Find both filter part numbers →