Trez83

This might sound like a dumb question, but is it OK to run 92 octane fuel with a 93 octane tune? I have not done it and was just wondering if there would be any ill-effects. For the record, I have the tune through Evolution Performance.

white_lightning

It's a bad idea, unless you like detonation...

Nuke

Only in an emergency and then very light on the throttle. But it'll eventually cause damage.

Trez83

That's what I figured. Thanks.

GlassVapor

Thats a touchy question, fuel loses a % of octane as it ages if you don't go to a station that sells alot of 93. You could think your buying 93 and if its old it could be way less.
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09 GT #250 Glassback, Vapor, Edelbrock E-Force,
etc.etc etc

Trez83

Yeah. That's why I've never done it. Right now, I have the 89 tune on - 93 is too aggressive for winter driving. Plus, 89 is at every station.