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Question about 91 octane

Hi guys, i have a question about gas. I know that in order to get these cars into their optimal fuel map you need to use premium gas. In my state (Maine) i have yet to find a single gas station that has more than 91 octane fuel. I have been lead to understand that this should not hurt my LS3, but that it could produce more power with a higher octane gas. My question is this is that true or not? If it is true is it worth it for me to buy a few cases of octane boost a year (Daily Driver in the summer months) to boost the 91 up to 93? Are we talking about the engine leaving 10 hp on the table with the crappier gas or are we talking about leaving 25+ on the table? Dont suppose anyone has a dyno sheet or two to illustrate the difference? Also, as the mods start to roll in over the winter, next spring i plan on having CAI/LongTubes/Full exhaust done at the least. Will adding those mods will I get good performance out of 91 octane? Would i need a tune (from the fuel aspect, i know long-tubes almost always necessitate a tune).

Thanks for any insight you might have,

I heard that alcohol injection boosts fuel octane by 20. So even if you put 87 octane fuel (lowest in california), it'll boost it to 107 which is basically racing fuel. Haven't done too much research on it yet, but something worth looking into.

Quote:

Originally Posted by Nathan Moreno (Post 2349600)

Alcohol injection? hmm well i had not thought of going there, but interesting... I always heard that was for really high boosted/juiced cars. I have no real plans (save for winning the Powerball) to stick a blower on this car. Just wanted so see if by using 91 oct i am leaving too many ponies on the table. If it will gain me a noticeable 20-30HP to go to 93 octane than it just might be worth getting a few cases of octane boost a year, if not, i'll stick the mods in, get a tune and be done with it..

I guess the real question here is, with 91 octane gas is my LS3 firing on the low octane spark table or the high octane one, any guru's know the answer to that?

Unless you do the fuse pull, your engine will be running on the lower octane gas table for a while. Takes a while for the system to recognize that your fuel is a higher octane.

Quote:

Originally Posted by Swytch (Post 2349570)

Two points of octane higher would allow a couple of degrees more timing during wide open throttle operation without encountering detonation. If you are talking a street car, I doubt whether the difference between a properly tuned 91 octane tune and a 93 octane tune would be distinguishable. Just be aware if you tune for 93 and then run 91 octane, your going to experience performance loss during heavy acceleration when the ecm detects knock and pulls a bunch of timing. Unless your intentions are to milk another couple of tenths off your ET at the strip, you would be better off properly tuning for 91 octane and forget the octane booster junk.