Has anyone on here ever noticed any better mpg with higher octane gas? I normally run the reg, and I wondered if going to premium would make a difference in either mpg or performance.

 

Nah, it won't make a difference, unless you program the Pcm to run on higher octane. For now just put the el cheapo in the tank

 

That sux... Won't higher octane keep your combustion chamber cleaner because it burns hotter? That's what I've always heard...

 

I guess, IDK, all i know that it is 45 cents more per gallon in my part of the country

 

holy crap! that's crazy...it's only about a 15 cent difference for me...

 

mpg advantage = generally none. the gas companies want you to believe that the more expensive, higher octane blends are premium, cleaner, better, somehow worth the extra money... 10 cents or more for 89 and another 10 cents or more for 91. it might be cleaner, but in the times i've tried it and tested mpg, i did not experience any improvement in mpg.

what higher octane really does is resist spark knocking, particularly in higher compression engines.
http://en.wikipedia.org/wiki/Octane_rating.
http://en.wikipedia.org/wiki/Octane
http://www.helium.com/debates/sbs/66...soline-premium

 

I believe that higher octane burns cooler...Helps reduce spark knock or pre-detonation due to high chamber temps. Higher octane is a waste of $$$ unless you have a programer that advances your timing.

 

So after I get my new TB, fix my plenum, do a new intake manifold, and get a Hypertech...it will be worth it...but for now it just lowers my bank acct...

 

i didn't really know i had a leaking plenum until i installed the hypertech programming to advance the timing, and it started pinging like crazy. higher octane gas was a temporary cure for a few months until i got around to fixing the plenum. it eliminated the ping.

 

well, to be perfectly honest, i don't know for sure. i haven't look under the tb, but i have the factory authorized upgrade sticker on my pcm, so i assume i have the plenum problem.