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 ...

The answer is yes: You can mix 87 and 91 octane gasoline without blowing your engine to hell. With that out of the way, let's discuss what mixing different octane fuels does to your engine in terms of ...

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 ...

Gasoline is a mystery to most hot rodders. For the most part, we just fill up the tank and forget about the fuel. The most difficult question is whether to step up from 89 to 92 octane. As you might ...