Cheers for the input fullas. im running 95 only because it the best i can get without driving 2hrs to the closest gas station that has 98, if i could i would trust me. Anywho had the same tuner same dyno and all the rest of it he did say he had to change the timing(maybe because of the lower fuel?) but now there is a fair knocking coming from the engine, still drives good though. I have to admit its been bloody cold lately compared to its first run and using Castrol Edge 5W-40 Just done a compression test and its 150 on all four not to mention i have a 1.2mm head gasket on there too. First