[jfmillr]

I agree with FXSTB, you dont have to be able to hear the knocking for it to be actually doing it. I realize the car manufacturer probably does make the car to run on any fuels that might be available in the area the car was sold in, but why would anyone want to put anything less then the best they can get at the station for their Porsche. If its a question of affording the gas, then maybe a honda would be better for some folk :/ Noone should ever short change on the extras for their high end car and if price is a factor I would suggest looking at other lines of vehicles that wont break your bank account.