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.

The higher the fuel’s octane rating, the less likely it is to prematurely ignite and cause engine knocking. phive2015/Adobe Stock We see the numbers every day at the local gas station, with gas sold ...

Q. Is it necessary to use premium 91 octane gas or can I safely use regular 87 octane in my 2017 Acura RDX? What about ...