by the way, i dont notice any power difference or poping in my exhaust using optimax, however i do find i get more k's from a tank of ultimate..
and on another note, Synergy 8000 (or whateva it is) and BP ulitmate are the SAME! they come from the same refinary, from the same tanks and often from the same trucks. its not unusual to see a bp truck in the Mobil on the pacific hwy. and i think the one on epping road too...
my 2 c...