Could someone please help with fuel selection for Evolution VIII? Owner manual recommends premium octane with 98 RON, and the best I've found is 93 octane. What about octane boosters? Supposed to raise octane level in a tank of gas I'm hoping to optimum level.

 

I am also a little fuzzy on the octane question. My stock EVO seems to run the same on 93 and 94 but this is on the butt dyno. Will the stock computer take advantage of better octane once you get past 91 or 93? Of course I can see how the custom engine management systems could be programmed to be more aggressive with high octane but my question is about a stock car.

 

By the way, solved octane dilemma with accelerator. Its a fuel accelerant, not octane booster. 32 oz. can raises 20 gallons of 93 pump gas to 97 octane. I put about 20 oz. in a tank and voila, one super smooth evo. This does not leave contaminants on sensors or damage anything. You wont believe this stuff, and won't want to run without it. This is how the car is supposed to work.