im wondering here does it matter what octane you run either it be 87,89,93,etc?

Sure it matters. You should of posted this on the Tech Board.

I run nothing but 87
and if I could find some 83-84 I would prolly be using it


use the lowest octane you can without pinging
you will get better mpg and power

the only reason to use high octane is high compression, boost, n20, or really advanced timing.

Yep, exactly, I only use 87 octane.

Dang, you guys use some low octane. The highest octane here was 92 but then they dropped it 1 less. So now CA people have to purchase 91. I always put 91 from 76.

I used to throw 91 in my gta but i tested it with some 87 and it ran fine with no pinging or anything like that so i use 87 now. I don't need to throw away any more money on gas . I used to use 91 in my vette (motor broken during a lube jock joy-ride when i dropped it off to have it smogged ).

And I alway thought the higher the octane the better... I thought it would give me more power

That's what I used to think, until people like RB83L69 and VAder had other things to say, on the TECH board. Forget the details though.

100 octane...11.5:1 compression

I run 91 or 92....I thought higher was better also....my car pings at 87 and slightly pings at 89, just slightly, so i use 91 whenver i can, and when i take it down to the drag races i put in nos octane booster, street formula cause i cant find the race formula.

you honestly can prolly run just as good if not better without the octane boost you are putting in your car

lower octane will have more energy to burn and will better use the energy it has

only reason to step up to a higher octane is if your car pings

HERE IN IOWA THEY CHARGE THE SAME FOR REGULAR 87 OCTANE, AND GASAHOL 90 OCTANE. THE 93 OCTANE IS ABOUT 10 CENTS A GALLON HIGHER. I RUN THE 87 OR 90 IN MY 305 CARBERATED TRUCK, AND ALSO EITHER IN THE 86 FIREBIRD 305 TPI. NO DIFFERENCE AT ALL. THE WIFE'S 350 TPI IROC ALWAYS THE 90, BUT DID TRY SOME AMACO ULTRA 93 OCTANE, BUT THERE WAS ZERO DIFFERENCE. WHEN I CHANGED THE 86 FIREBIRD TO A 406 TPI, I STAYED WITH THE 90 OCTANE WITH NO PROBLEMS AT ALL. I USUALLY JUST PUT THE 90 OCTANE IN SINCE IT IS THE SAME PRICE.

9.5:1 CR, 7 degrees advanced base timing, 85 (yes, eighty-five) octane.

I just filled my car with 87 octane today I'll see what happens...

Hmmm makes me rethink my gas situation... when I bought my car the guy said that he ran 87 and it was fine... I thought that that was a little low for a V8 and I thought 89 would be more apropriate, but the difference between 89 and 93 is only about 10 cents and I figured why not just treat it nicely. So I've been running 93 thinking that it maximizes the power just slightly... mind you I know it doesn't make more power...

SO I should really be running 87 shouldn't I? It doesn't shorten engine life and I would notice pinging if that were actually going on right?

i run 87 octance with a lil more base timing

I run 87 octane most of the time, although I notice a small amount of pinging while driving up a steep hill, or under sudden hard acceleration. When I use 91 - 94 octane there is absolutely no pinging whatsoever.

Oh yeah, in the 1988 TransAm GTA owners manual GM recommends 89 octane.

93 Amoco Ultimate only.

yep 87, burns faster....more power...lol just the oppposite of the others. in my 5spd we have the timing adavnced to under real hard acceration it pings. I think insead of backing off the timeing I will run 89. If that does not stop it I will back off and return to 87.

I run 89, only because of advanced timing.

First of all, I'll say I'm not looking for a newby bashing or anything, trust me when I say that I give all you guys/gals the utmost respect. I may be a newby here, but not to Camaros in general. They've been in my family all my life. I've run 90 octane or higher in my camaros ever since new, even when I was down to my last dollar, I'd still opt for the 93. Force of hibit I suppose, but I wasn't gonna chance running anything less. In reading the information on this board, I was shocked to read what I saw. I couldn't wait to get to the Amoco to fuel up with 87!!! My ***. Am I missing something here? In running 87 octane, I have totally forgotten why I loved my Camaro so much. I was so upset. My car has NEVER, and I repeat, NEVER performed so badly. No pinging, but it just doesn't have near the "seat of the pants" feel as it normally would. I know I may be out of place here, and believe me when I say that I'm not doubting anyone's intelligence. BUT I just don't get it. What am I missing here? I found myself today driving around like an idiot, just so I can run all that cheap gas out so I can get down to the Amoco for some 93. I apologize for taking so much time and space. I just had to express my concern for this topic.

Could be all in your head. anyways I run 87 with a $hitload of mods. Head, cam ect. but I have my timing set at base 6*

Firebird 8.5:1, 355, 12* of base timing 85.:rockon:
Dead Camaro 11.5:1, 355, 13* of base timing 91. Would ping like a motha with 85 and 87 even droping the timing dident help.
76 Pu, 13:1, 355 13* base timing, 115. Oh thats 111 octane.

hey, you should turn this into a POLL!!!!

it could be in your case Thundering Z03 that you might not have had ping or anything but instead b/c of something in the setup in your car that you are having a bad flame front

or maybe even two flame fronts

Thank you all to your comments to my brain dead concern I suppose. This may sound even more ignorant, but anyway, is it possible for a car to become dependant to a higher octane fuel? Considering that all I've ever run is high test. If this question deserves a smack in the forhead, just disreguard my remark.
Thanks

hehe, like an alcohol tolerance. no, they don't become dependent. i run 93 in my car but only because i have 10:1 compression. Look out for ethanol in gas, the station is legally bound to have a sign saying that they have ethanol in their gas (at least in Mich.) It's not good for the car and burns faster than gas, they do it to save themselves money. sunoco seems to be a culprit around my parts.

just because one guy can get away with 87 doesn't mean everyone can. It is better to run too high of an octane than too low. Variables like elevation, engine condition, engine temperature, ambient temperature, timing, compression, etc. determine the octane needed. Too high an octane rating will decrease power to an extent and can increase combustion temperature slightly. Too low of an octane rating can induce detonation which will destroy an engine. My friend's wife decided she'd take the "cheap way out" and use 87 in their 87 GTA without telling him and she scrapped the motor within a couple months. He had headers, 1.6 rockers, the free mods and had bumped the timing up slightly. Many people don't give detonation the credit it deserves. Let me put detonation into lay-man's terms. Imagine every time a piston came to the top of the bore, hitting it with a hammer. That's basically what's happening every ping during detonation. It eats the top of pistons to pieces and pounds rodbearings to death. If you live in a cold climate and don't run your car like a striped-assed ape then you will be fine with 87 but if you live in 100 degree heat with high humidity in traffic and demand the extreme from your car, run the best you can get. Eventhough you can't audibly hear detonation, it doesn't mean it's not happening. The only way to be sure is to monitor the knock signal using a scantool. I wish a product like the Scanmaster II was available for the TPI cars like it is for the LT1 and 3.8 Turbo cars. This is an invaluable tool worth 5 times what it costs. It is a display no larger than a radar detector that will tell me all the info of a scantool and will record the highest knock counts and o2 levels for the perfect of tuning. I run 110 octane in my turbocar but that's with 21 lbs of boost. I always run 104 in my 383 with 10:1 just to be safe. I'd rather sacrafice a small amount of power to keep my motor in one piece. Determine what your car needs, not what someone else can get away with. If you're not sure, use the better just to be safe.

Snakeskinner, thank you so much. That's the exact response I was looking for. I feel much better now

i always heard that there is no more power in, say 115 octane turbo blue, than in 87 octane pump gas. octane rating is just a fuel's resistance to pre-ignition due to high compression. high compression and low octane will cause the fuel to ignite before the spark plug fires. like in a diesel engine which ignites the fuel by shear compression alone with no spark plugs. i'd use the lowest octane you can run without gettin a spark knock or ping. my motor isn't even 10:1 and it runs fine on 89 octane gas. only time i ever go for a higher octane is every once in a while i'll put a 1/4 tank of sunoco ultra 94 in and run the pi$$ out of it to clean any carbon out. that stuff burns really clean and gets all the gunk out.

Rich

This topic has come up many times before. Even though it is true that lower octane gas will maximze power by burning quicker, it also requires less base timing, therefore, decreasing efficiency and throttle response. I'm running only 7, maybe 8* of base timing on an otherwise stock 305 and I still get audible pinging when the motor is cold . Yeah, tell me that's weird. It doesn't ping at all once it reaches normal operating temperature. I have tried 87 octane many times before. Too many times for it to be my imagination that my car runs like crap on lower octane fuel. But that was back when my timing was pretty retarded to begin with. Maybe I'll bump the timing back to 6* and try some 87. I would really like to use lower octane gas if at all possible without giving up any throttle response and power.

93.... Sunoco Ultra 94 if possible.

If regular (87) is $1.10 and Super (93) is $1.20 then over the 15 gallons that our tanks hold, putting Super in as opposed to regular, you spend an extra $1.50. I find that to be a worthwhile investment to help keep the SBC going as long as possible. (I saw flames coming for using 93 or 94 in my 9.3:1 L98, so I figured I'd explain my logic.)

It matters on my ZZ4TPI. I've always run 93 octane and never have I seen the computer pull timing. The other day I put some 89 octane in. The computer was pulling 3 to 4 deg of timing at 3/4 throttle! Guess that 10.5:1 compression is no joke!
I've proven time and again I get better MPG with higher octane, but I'm not sure if it evens out in the end. I.E. added expense of the gas -vs- more miles on the tank.