03GMC

iTrader: (2)

So I called wait4me trying to see what he offered.....I asked him about tuning and what kind of gas I could use. He said that he would do a tune and that the computer would adapt to the gas I put in my truck. He said I could run 87 all the way up to 100 something and that the computer would sense this and adjust to the type of fuel I was using at the time. Is this true?

Torque_Wrench

iTrader: (13)

YES....that's true.....it's called a flip tune. I have the same type of tune myself.

dc_justin

iTrader: (13)

To clarify, there is no octane sensor in the truck, just a high and low octane spark table. It will start at the high octane table, and if insufficient octane is used, it will knock. The PCM will pick up this knock and begin to adjust the timing down towards the low octane table. It will constantly attempt to raise the timing up towards the high octane table, but as knock is detected, it will be stopped.

Quik

iTrader: (7)

X456789

so you were just slanged BS and justin just clarified it up

gmforlife

iTrader: (2)

That's exactly how the timing tables work!!!!

allenmehrer

but does the stock PCM adjust up to 100? whats special about the adjustability of the wait4me

DanaliHD

iTrader: (5)

as far as i remember, the stock high octane table has a much lower timing at wot than a custom tune would. so, no.

RandomHero

iTrader: (24)

That is very true. There isn't a whole lot you can do with running 87 octane, but you can add quite a bit of timing with 87-93 octane. I don't know if I'd run straight 100 octane in my truck though.

by the way listen to Justin. He won't steer ya wrong.

Country Boy

iTrader: (24)

no, the high octain timing table is set (doesnt matter the octain. Ususally set for 93) so if you put 100 in it, it will just be a waste of $$$ unless the timing was set too high to begin with causing knock.

Justin described it right.

03GMC

iTrader: (2)

So what you guys are saying is I could run 87-93 but the performance would change? Like say if I was taking a trip and was just going to have the cruise on 80 and not really looking for hp....I could just run 87 then? Also would the mpg change between 87-93?