Originally Posted by BMW-M-Mexico
The use of a higher octane fuel than required, is a twofold mistake. You are wasting money and can possibly do damage to the engine. Using a higher than require octane rated fuel will not increase performance,
As far as I know this is false info. Higher octane will not cause any damage to your engine. It will only cause damage to your wallet. It does have the possibility to improve performance since higher octane fuel burns slower. The slower burn of the fuel is good because it will continue to burn for a longer period during the power stroke of the engine. This is a benefit because power will continue being created during the expansion of the burning gasses for a longer period of time instead of a quick explosion then nothing more for the rest of the power stroke. For best performance you the most complete and slowest burn of the fuel.