SAN FRANCISCO, CA (KRON) —  A new study explains how more expensive gasoline may not necessarily be better quality for your cars.

According to CNN, the American Automobile Association (AAA) says premium gas may not always live up to the hype.

The association tested regular and premium fuel.

The research shows only some engines receive benefits from premium gas.

The majority of cars showed no difference.

AAA recommends if you use regular fuel, use the ones labeled top tier.