when I had a the knock I used 95, but change to 98 now and I also change a igntime back to 1 deg and it works well.I just wonder if I keep driving like this will it be a lot of effect to the engine and also sone one had told me about the workshop can "clean up" the knock when I bring car to do dyno tune, what they acttually do to "clean up" the knock and what is the acttual dammage knock cause to the engine, for exp engine crack, blown, freeze.. etc.
Coz i'm only do daily drive so I'm still consider about the running cost, for sure get the car tune up to a proper performance can be cossy in long term drive. And fact that the previous owner had tuned it back from the performance just be cause the fuel economic.
Cheers,