Filters

Does a New Engine Air Filter Improve Gas Mileage?

The old advice says a clean air filter saves gas. That was true for carburetors. For the car in your driveway the honest answer is different, and it still gives you a reason to change the filter.

What the Department of Energy found

Replacing a clogged air filter on vehicles with fuel-injected, computer-controlled gasoline engines—such as those manufactured from the early 1980s to the present—or diesel engines does not improve fuel economy, but it can improve acceleration.

U.S. Department of Energy / U.S. EPA (fueleconomy.gov), Gas Mileage Tips - Keeping Your Vehicle in Shape

A modern engine measures the air coming in and trims the fuel to match. A dirty filter means less air and less fuel together. Mileage holds steady. What you lose is power at full throttle.

While that advice was sound for carbureted cars, a U.S. Department of Energy study found that air filter condition has no significant impact on the fuel economy of modern fuel-injected engines, although a badly restricted air filter will reduce the engine’s maximum power output.

AAA, Changing Your Cars Engine Air Filter

Older cars are another story.

Replacing a clogged air filter on an older vehicle with a carbureted engine can improve both fuel economy and acceleration by a few percent under normal replacement conditions.

U.S. Department of Energy / U.S. EPA (fueleconomy.gov), Gas Mileage Tips - Keeping Your Vehicle in Shape

GP075GP075 Engine Air Filter

Fits Toyota, Lexus, Jeep and 1 more

4.7 · 6,407 ratings

$15.97

GP171GP171 Engine Air Filter

Fits Toyota

4.7 · 4,585 ratings

$13.87

GP165GP165 Engine Air Filter

Fits Honda

4.8 · 2,320 ratings

$15.87

GP883GP883 Engine Air Filter

Fits Ford and Lincoln

4.7 · 941 ratings

$14.87

So why change it

Three reasons remain. The engine pulls hard again when you merge or pass. Grit stays out of the intake. And a panel filter costs little next to the parts it protects: an EPAuto GP filter starts at $11.87.

We will not promise you extra miles per gallon. On a fuel-injected engine a new filter does not deliver them.

Check it with a light

If light passes easily through more than half of the filter, it can be returned to service.

AAA, Changing Your Cars Engine Air Filter

1. Open the air boxMost have two to four clips. No tools on most cars we cover.
2. Lift the panel outNote which side faces up. Tap out loose leaves and bugs.
3. Hold it to a shop lightIf light passes through most of the pleats, put it back. If the pleats are dark and packed, replace it.

In a relatively clean city or suburban driving environment, an air filter may be good for 20,000 miles or more between changes.

AAA, Changing Your Cars Engine Air Filter

We recommend a new EPAuto engine filter every 12,000 miles. Dusty roads fill a filter faster than clean city streets, so let the light test decide.

Quick answers