What kinda 93oct gas?

[PastorTree]

Ok so its obvious that Sams Club, Valero, and 7 Eleven gas cannot be used for a 93 oct fuel perf tune. What gas should I be using to get that tune? Shell, Exxon, BP, or..........?

[Mike_Levy]

Exxon, Mobil, BP or Sunoco. Never use Shell. Their additives cause knock. I've used Lukoil a few times on highway trips and it seems okay, but never tried it for performance driving. I have Valero in my Audi right now. Tank was empty and that was the closest station. Car seems to like it. That doesn't mean other cars will (the Audi has Direct Injection, not Port injection like the Mopars).