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.

DENVER (KDVR) — Gas prices are fluctuating across the country, and a few states offer a “cheaper” octane option that isn’t found in most places. It has to do with the altitude. Most states have the ...

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 ...

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated. DENVER (KDVR) — Gas prices are fluctuating ...