Octane ratings refer to the stability of fuel, and dictate at which pressures the fuel will spontaneously combust. Engine knocking can happen when the octane rating is too low, resulting in pinging ...

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 ...