Learn when premium fuel is actually required, what the different grades mean, and how to avoid paying too much.

87 octane gasoline, often called "regular" gas, is one of the most commonly used fuels in the United States. But what gives it that 87 rating is a word you've probably heard a time or two: Ethanol.

We may receive a commission on purchases made from links. Most gas stations have three options that you can put in your vehicle: regular, mid-grade (plus), and premium. These labels are also often ...

The demon of engine knock is something an owner of a traditional high-performance Pontiac knows all too well. An engine designed when 102-octane high test was at almost every fuel station in the ...