It will not make an improvement, as a matter of fact it will probably slow down if anything because of the slower burn rate of the higher octane rating.

Now running this gas will allow for you to throw a bit more timing at it, and possibly some extra fuel in the tune, but all in all if the tune is not adjusted for it, it is just a waste of time.

Unless you a running alot of boost, or spraying the **** out of it, this will help with detonation on a hot day!

Hope this helps...

Seth

 

yep what he said!!

 

You'll probably want to tune for the more readily available fuel. Road trips and such

 

This is a good idea and the very reason I'm not running E85 in my truck. Additionally, keep in mind that these motors are not high compression. You might be able to add more timing, but you may not be doing the motor any good.

Best thing to do is dyno your current timing, fill up with 94 octane, and then dyno with extra timing and see if you even see a positive change in power.

 

I believe running a higher octane then necessary can also have a negative impact on fuel economy because less fuel is consumed efficiently. It can also lead to excess cat wear due to more unburnt fuel passing in the exhaust.

 

Thanks.. Guys.. It makes sense.. Plus I do use this bad boy for long trips... I just thought adding a little to mess around i'n the streets ..

 

This is an interesting discussion. I do have to ask though, the 91 in TX isn't premium, but is in other places. Is the 91 here the same as everywhere else?

 

Yup, here in AZ we have 87 regular, 89 midgrade, and 91 premium. When I lived in MI, premium was 93 except at Speedy Q, where it was only 91.

 

OK cool, so I will get a 91 tune then. Thanks!