If I custom tune for 93 or 91 octane, how much of a performance boost is there?

If I custome tune for 93/91 and fill up with 87/89 will the car adjust back down to the lower octane, no pinging, until I fill up with 93/91 again?

 

I have a C&L CAI with an SCT XCal2 tune from Brenspeed. I'm running a 91 octane tune. It's a noticeable difference over stock. That's all I can say about that. I will have it dynoed in a couple weeks to see the actual improvements. If you are running a lower octane fuel with a higher octane tune, I'm sure you'll be OK as long as you don't have any pinging. Just don't push the car too hard until you fill up with the correct octane.

 

#1 .. yes you should .. I did..

#2 NO .. you might get some damge to the engine .. it is not worth the extra money to cheap out on your engine.. $.10 extra per gallon.. holds 16 gallons..
so $1.60 in my book is not worth the chance of possible engine damage..

JMO


Rex