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 ...

Add Yahoo as a preferred source to see more of our stories on Google. With the price of regular unleaded gasoline still in the $4-a-gallon range, the comparative price of premium is kind of a bargain ...

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 ...

With the price of regular unleaded gasoline still in the $4-a-gallon range, the comparative price of premium is kind of a bargain at many stations. Really. When the price of regular surged this spring ...