Yeh I use Shell 91 octane with my Dinan chip.
I use the same 91 octane before the chip with new motor.
Old motor I ran 89 octane I believe the middle grade, no problem.
We used to race a 2002 on lower octane because it actually ran better.
My question is whats the best brand shell, chevron, mobil etc?
Its all the same base gas run through the same pipe out here.
Then Shell or Chevron put in thier additives detergents etc.
There is a great del of info on this subject out there.
Bottom line if chipped use high octane or risk detonating your motor LOL.
PS if you dont have a chip and want one for i motor and -173 ECU ask me about it offline.
'87 325is Delphin Metalic
Last edited by Rfitz25; 03-19-2007 at 06:33 PM.