Octane

[eagleguy]

Is there a big difference performance wise between 92 and 93 octane on a motor with mild mods?

 

[turbo nasty]

Air temp..Target AFR...timing..etc all play into this not just octane but on paper the higher the octane the better. With pump gas modern chip (TT or Ext) 91-93 and decent timing on a bolt on engine 16-17 is about it. Mind you WOT in third is where KR will show its face due to 4th gear being 1:1 and loading the engine.

 

[earlbrown]

Is there a big difference performance wise between 92 and 93 octane on a motor with mild mods?

If your engine is happy with 91 or below there will be no difference at all.


If your engine needs 93 and 92 isn't enough, then it will be the difference between running and coming apart. I seriously doubt that's even possible though. The sun could go behind a cloud and change rules and gas isn't that consistent batch to batch. Not to mention summer .vs winter blends.

 

[NY Twin Turbo]

Your engine must be tuned to take advantage of octane. That's why guys wick-up the boost and timing at the track. Just adding higher octane fuel wastes money and doesn't take advantage of it's potential. So basically, the answer is no. What adding 2 or 3 octane does is provide the necessary safety margin for cars that are used in variable situations that sometimes can be less than ideal.

If you are on the very tip of your tune with a specific octane, running as much boost as you can, whether it be a chip or XFI, and one day you decide to put a lower grade fuel in, then you will hurt something. Not a lot of typical street guys are on that edge. And if you are........you shouldn't be and your too damned close.

But now that I have said that......use 93. It's the safer choice. But don't expect to "feel" a difference. Because if you do, it means your computer was pulling timing when you had the cheap sh!t in it. And that's NOT a good thing.