I run 94 for safety and tuned on it at 12:1 CR. But the other day I had to get 91 because I was stuck. I took it all the way through VTEC and ripped on it hard just to see if there were any side effects like my knock sensor kicking in. Nothing. Makes me think my timing is fairly conservative. Anyways, as long as it were safe does a lower octane gas keeping constant timing and fuel make more power? Or is it unrelated?

I would think running too high of an octane would resist combustion and hurt power, no?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by satan_srv &raquo;</TD></TR><TR><TD CLASS="quote">I would think running too high of an octane would resist combustion and hurt power, no?</TD></TR></TABLE>

Yup

91 is still a premium gas, I run it all the time (forced to in cali). my comp ratio is ~11.2/1, no knock, I hope. Also depending on the ecu, a chipped one doesn't look for the knock (from what I was told.) Run the 94 though, better safe than sorry.

 

Th lower the octane you have with no knock, the better it is for your engine. The only thing higher octane does is slow down the burn of the fuel which prevents detonation. Unless your setup would higher octane to prevent the detonation, save your money and stop losing power. It all depends on the setup.

 

Yeah that's what i thought. Better safe than sorry is a good way to look at it. I wonder how much difference it actually makes, probably not as much at 12:1 compression.

 

ive always had wierd feelings about the sunoco 94 gas(i assume thats what your using )...id rather put in esso or petro..

have you tried the sunoco 92...

 

Yeah I don't know about that ethanol BS...I'd rather not have it in there.

 

a few of the aem ems tuners that i talk to up in yankeeville say that the sonoco 94 is junk. i have seen where a few of them pull more power with reg 93. they get knock when going to the 94. this is 6-800hp supras and such, not 200hp hondas so i dunno. i have never used it, all we get is 93 or 100 down here.

but normally for na use the lowest you can get away with. if you can keep advancing the timing and gaining power till it knocks then you need more octane, but if advancing dosnt gain you power and you're not getting detonation then try a lower octane.