octane question

**KING Z28 HAWK** · 03-03-2008, 08:28 PM

When changing up in octane any things I should replace or do? Any info is appreciated. Thanks.

**0rion** · 03-03-2008, 09:07 PM

are you talking about going from 87 to 93 or something? Or race gas?

**KING Z28 HAWK** · 03-03-2008, 09:10 PM

yeah 87 to 93

**Wesman** · 03-03-2008, 09:12 PM

Originally Posted by KING Z28 HAWK

yeah 87 to 93

Only thing I would do is reset the PCM by disconnecting the battery for about 20 minutes. That was the computer can re-learn its parameters based on the higher octane fuel. There is nothing you can physically do to adjust it though, its all done automatically in the PCM.

**totalkos** · 03-03-2008, 11:24 PM

why would you put 87 in something anyway? especially a z28, dont they require 91 and up? i know mustangs say 89

**redls1** · 03-04-2008, 06:28 AM

Wont the computer learn on its own? It will take a tank or two before anythng is realized. By running better gas you"ll get you get less knock, if there was any, Which doesnt that equate to more timing and thus more power?

**gnomee** · 03-04-2008, 05:38 PM

According to the owners manual you should run 91 or the highest octane available.

The computer will learn on its own but unless you just don't like re-programming the radio a battery disconnect like said above is probably the best route to go so the computer is not playing with the timing and Air Fuel ratio, probably isn't the best for Plug life.

Put some high octane in that baby, it will like it.

**hec33** · 03-31-2008, 06:11 PM

It says you can run whatever in the manual, but it says for best performance use premium... The computer just learns if it senses a knock

**Speedy_Gonzales** · 03-31-2008, 06:15 PM

nothing but 93 here

**drummer52910** · 04-01-2008, 06:48 PM

For the most part in my car i run 91 octane because thats whats widely available around here. Every now and then i put in a tank of 93 and seems to me like im losing a slight bit of performance by doing this. Could this be because im not giving the computer enough time to calibrate for the 93?

**hec33** · 04-01-2008, 07:04 PM

Originally Posted by drummer52910

For the most part in my car i run 91 octane because thats whats widely available around here. Every now and then i put in a tank of 93 and seems to me like im losing a slight bit of performance by doing this. Could this be because im not giving the computer enough time to calibrate for the 93?

You should see no change, or barely any performance gain from doing that... It definately should not lose any power, unless it is bad gas.

Theoretically, it should reduce the chance of detonation which would let the car run more timing, and give you more power. Without any timing change, there will be absolutely no change in horsepower whether you use 91 to 120 octane... But there should not be any performance lost at all

**jimmybling31** · 04-01-2008, 07:08 PM

Originally Posted by SpeedAddict38

nothing but 93 here

you know that gas in our area is actually better than the rating. our 87 if tested would come out to 91. and our 89 comes out to 92. the 93 comes out to 95.something. I read a little about how the ethanol they are putting in it now in our area raises the octane of it significantly, but they can't rate it higher because of some regulation that says they have to base it off the gas itself not the ethanol added to it. so if you wanna runn 89 in our area it's completely fine. I normally run 93 if I think I might go to the strip, but 89 almost all the other times to save a little cash.

**hec33** · 04-01-2008, 07:16 PM

Originally Posted by jimmybling31

you know that gas in our area is actually better than the rating. our 87 if tested would come out to 91. and our 89 comes out to 92. the 93 comes out to 95.something. I read a little about how the ethanol they are putting in it now in our area raises the octane of it significantly, but they can't rate it higher because of some regulation that says they have to base it off the gas itself not the ethanol added to it. so if you wanna runn 89 in our area it's completely fine. I normally run 93 if I think I might go to the strip, but 89 almost all the other times to save a little cash.

Yea, I saw Etahnol enhanced fuel, or whatever you call it, when I went to Atlanta for spring break. We don't have the privelege of that here yet. Here, if you put anything under 93, you run the chance of water in your tank.

**jimmybling31** · 04-01-2008, 07:33 PM

Originally Posted by hec33

Yea, I saw Etahnol enhanced fuel, or whatever you call it, when I went to Atlanta for spring break. We don't have the privelege of that here yet. Here, if you put anything under 93, you run the chance of water in your tank.

eh. I have run 89 for a while no problems. I'm not too scared. i had to run premium in my last car, so being even able to run lower is nice to me. lol

**hec33** · 04-01-2008, 08:00 PM

Originally Posted by jimmybling31

eh. I have run 89 for a while no problems. I'm not too scared. i had to run premium in my last car, so being even able to run lower is nice to me. lol

Lucky you...