At the moment I am considering importing (Japan) either an EVO6 GSR or Impreza STi 6 Type R. Anyway on the scooby forum there is masses of talk of octane booster. As the maximum I can get is 97RON fuel do I need to worry about octane booster and knocklinks and all that ? I don't want to damage the engine basically. I don't think the EVO6 was ever officially released over here (UK) as they were all grey imports so can I assume there was never any major problem with sourceing the correct fuel or that the highest RON petrol was always used without need for octane booster ?

Any comments would be greatly appreciated.


Daz