ORIGINAL: DwightMann

The octane rating of gasoline refers to the resistance of the fuel to preignition and has nothing to do with the energy of the fuel. High compression motors such as race cars are more prone to this which is why they need the higher octane. It doesn't hurt to use the higher octane, but if you car ( or plane ) doesn't ''knock'' with the 87 octane, anything higher is only a waste of money.