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.

If you've ever fueled up in Colorado, you might have noticed something unusual about the gas octane ratings at the pump – specifically, the availability of 85-octane gasoline. This lower octane fuel ...

DENVER — When you last filled up your car, do you remember how much it cost? You probably do because it was so high. There is a good chunk of Colorado drivers who could save money right away by ...

John Paul, AAA Northeast's Car Doctor, answers a question from a reader who recently visited a service station offering both 87 and 88 octane gas. The Car Doctor answers a question from a reader who ...

DENVER (KDVR) — Gas pumps in some Western states look a little different than the rest of the country. Most states have the option of choosing octane ratings of 87 (regular), 88–90 (midgrade) and ...