I dont touch Optimax unless I have no choice (like running out of fuel in the middle of north sydney)
I usually fill up with Synergy, as I get a lot better fuel ecconomy, and my car doesnt ping on it (it does ping with optimax, and vortex)
I have tried BP Ultimate a few times, and thats pretty good!! no pinging, and good fuel ecconomy.
I also use Nulon Pro Strength Octane Booster every now and then. good stuff !! (better than the 104+ crap I tried once)
FPV - Tickford Club of NSW