2 replies to this topic

[Todd Tagget]

Everything I read says higher octane doesn't result in more performance.. Just prevents detonation especially with turbo boosted cars..

So why would we not run 87 vs 91 in our cars ?

 

[nballard76]

Higher octane fuel allows you to advance the timing more which results in more power...

[Steve Scheifler]

The key is that more “than it needs to suppress knock” will not increase power and will even reduce it. Every molecule of knock-suppressing additive displaces a molecule of actual fuel. You might get away with 87 under ideal conditions or it might be a problem. Conditions aren’t always ideal. If you want to optimize ignition timing and air/fuel, it’s safest to run at least 91.