....Example; I know a guy who built the motor in his Ford p/u. It was a while back so I don't remember the exact details as in engine size, compression ratio, etc, etc... BUT what I do remember is he built the motor with the compression ratio to the high side of what was recommended, it pinged AND he used to have to dump a can of Octane Upper in every time he filled up. Trust me, it became a real pain in the a**, REAL QUICK..... WHY take the chance??? bill