Premium gasoline sounds like the automotive equivalent of ordering the expensive steak. The pump labels it “premium,” so it is easy to assume your engine gets something better.
That assumption can make an ordinary fill-up unnecessarily expensive. Premium fuel mainly offers a higher octane rating, which helps engines resist knock. If your car calls for regular gasoline, paying more at the pump usually does not give the engine extra power, better mileage, or a special dose of mechanical happiness. AAA testing found no meaningful performance or fuel-economy advantage for vehicles designed to run on regular fuel.
