If you're a casual driver and don't pay much mind to the specifics of fuel composition, filling up at the gas station can be confusing, especially if it's a new car. Whether you're topping off a ...

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.