Timing and Fuel Octane

[oztracktuning]

Can anyone give me a typical figure for the amount of timing advance difference that an engine will take on 95 octane (RON) fuel versus 98 octane (RON) .

Just interested to know how much more timing a car tuned today on 95 can take?? Just good to get in the ballpark.

[GMPX]

Experiance with my own car is about 3-4 deg down (from about 23-24) at the top end from 98 - 91, I've never used 95.
Problem on 91 seems to be the low RPM WOT and light throttle, pretty hit and miss there, other issue is the 95RON in Aus like what the supermarkets sell is probably even worse than a good brand.

Cheers,
Ross

[oztracktuning]

Thanks Ross. So maybe 0.5 deg for Octane point? So 1.5 degrees??

[ringram]

Yeah thats what Id say. 95 is like 91 US and 98 like 92.5 (93) according to wikipedia anyway.
1 to 1.5 sounds about right.