Wrong gas

DaGeneral · 02-20-2006, 06:43 PM

So I recently bough my SS and the first time to pump gas came and I never really thought about it and pumped 87. Well this was done last night and tonight it just didnt run the same. I called the previous owner and he said the car had only seen 93 octane fuel- he and the previous owner never put anything else. Im hoping this is the reason why the car ran a bit sluggish... Any thoughts ? What do you guys pump? Im guessing 93 Octane and now I feel bad for my car since I pumped 87 . Its not because its cheap its just the thing I had pumped forever so when it came down to it I never thought about it.

Should I worry about damaging the engine because of this gas? Or just let it be and change gas next time ?

Would this lead to the car running a bit sluggish?? Having never run on 87 and then having to run on it?

Im contemplating draining it.

I think I should be more specific. The throttle response felt a little slower than before. That's what was different...Thanks guys

**jeffsredt/a** · 02-20-2006, 06:52 PM

i thought the same thing when i got my t/a i put 87 in and noticed sluggish and a little pin action to but then i switch to 93 octane and thats all i run but i don't think it hurts the car at all. But if others know differently let me know too

quicky06 · 02-20-2006, 06:57 PM

as long as you dont get on it and go over 3k rpms you wont have a problem once it warms up

**02z28ls1** · 02-20-2006, 07:07 PM

The factory service manual states that it's not harmful to run lower than 91 octane-but you will notice a loss of power (probably fuel mileage too,just a guess).If you didn't fill it up,go put in some 91 or higher to help it out.Around here we can get 93-never ran anything any different myself.

**jeffsredt/a** · 02-20-2006, 07:10 PM

now i only put hte shell v-power in and runs great

DaGeneral · 02-20-2006, 07:16 PM

Originally Posted by quicky06

as long as you dont get on it and go over 3k rpms you wont have a problem once it warms up

Exactly. It felt sluggish AFTER 3K...

Thanks guys

**SeVeReDiStOrTiOn** · 02-20-2006, 10:39 PM

Far as I understand it, the puter senses if it's low or high octane and adjusts the timing accordingly...which causes a loss of power for 87 oct.

**SteveC** · 02-21-2006, 04:01 AM

The PCM probably retards timing when lower octaine (sp) fuel is used, it will readjust once you go back to higher octaine (sp).

SteveC

**third_shift|studios** · 02-21-2006, 06:19 AM

damn, i didn't know that about the computers...pretty spiffy!

quicky06 · 02-21-2006, 11:37 AM

yes but it takes alot of it to make a diffrence. generaly it will take 2 or 3 tanks before the computer fully adjusts to the diffrent octane.

**brushrunabout** · 02-21-2006, 02:24 PM

Ive been testing 93 the last 2 tanks. otherwise 87 for the last 60,000 except for a few 93 fills for Sat driving. Mostly highway and unless infrequent open road rarely go over 2,000 rpm.

93 does give a noticable acceleration boost and better exhaust sound. My milage may have gone up 1mpg if that from 87 octane. I average 22 mpg on the 87 with 70% highway and got 23MPG with the 93 plus a little more fuel dumps on on ramps.

No mods so the highway driving doesnt care. Definately worth the $2 tank if you have room to enjoy it. Still makes 98% of cars easy prey at 87.

For quickest reset you could pull the ECM/PCM fuse so the car has to relearn when you put in 93 again.

**ReBop** · 02-22-2006, 04:23 PM

Pour in a bottle of octane booster and drive the tank empty.

Then fill it up with 93 from now on.

Get in the habit!

**02z28ls1** · 02-22-2006, 06:50 PM

I could be wrong on this but I believe the computer is using the knock sensors to tell it to retard the timing,so the effect is immediate.If you have the ability to reflash the PCM you can program it to the fact that you will always use 91+ and this will eliminate the possibilty of it rolling back the timing.It's worth some horsepower (and fuel mileage)because it's not looking for knock problems being caused by octane and will bump up the timing with more "confidence" if you will.Like I said this is my educated guess.