101 Octane
Thread Starter
Instructor
Joined: Oct 2004
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From: OKC Ok
101 Octane
Hi,
Im new to this forum. I just bought a 91 c4 with a testtorosa bodykit/ zr1 wheels. Its pretty much stock for now besides exhaust. I was wondering, does 101 octane really help your performance and are there any negative side effects. I put some in my car acoulpe days ago when it was on empty, like only a gallon to see for myself. I can't quite tell for sure, it seems like the engine runs smoother but I don't know if it will actually pull better numbers? Thanks
David
Im new to this forum. I just bought a 91 c4 with a testtorosa bodykit/ zr1 wheels. Its pretty much stock for now besides exhaust. I was wondering, does 101 octane really help your performance and are there any negative side effects. I put some in my car acoulpe days ago when it was on empty, like only a gallon to see for myself. I can't quite tell for sure, it seems like the engine runs smoother but I don't know if it will actually pull better numbers? Thanks
David
Team Owner
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From: I'm the walkin dude I can see all of the world...
St. Jude Donor '03
Originally Posted by Nathan Plemons
If your engine is stock you'll actually make a good deal less power on 101 octane.
I gotta ask why?
Drifting
Joined: Oct 2004
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From: Patchogue NY
Welcome to the forum. I normally run 91 to 93 octane for my 91 coupe, and I've had no problems. 101 sounds to be a bit of over kill, especially if the car is close to stock. But then again, I'm no expert of this forum. Good luck.
Joe B.
Joe B.
Racer
Joined: Aug 2004
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From: Buffalo Grove IL
Remember, octane rating basically corresponds to how hard it is to start the air/fuel mix on fire. Higher octane is great with higher compression engines, where you don't want the mixture lighting off prematurely, causing detonation. If your engine runs fine on 91/93 octane gas, use it. Otherwise you're just wasting money.
Octane is probably one of the most understood concepts, I can't count how many times people have told me, "oh yeah, put 107 octane gas in the car, it flies now!". Umm, yeah...
Ben
Octane is probably one of the most understood concepts, I can't count how many times people have told me, "oh yeah, put 107 octane gas in the car, it flies now!". Umm, yeah...
Ben
Race Director
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Originally Posted by aklim
It might contaminate your O2 sensor, IIRC
Truth be known you want to run the LOWEST octane fuel you can while maintaining full spark advance under the worst conditions. Running a higher octane fuel than you need costs you horsepower and fuel economy. Some people will argue against this until they are blue in the face but the fact of the matter is that they are wrong, period.
If anybody claims a horsepower increase, ask them for the dyno chart or ask to see their timeslips. If they claim better fuel economy ask them to see their detailed long term records. I assure you that they will not be able to produce either. People like to think that because it costs more, it must be better.
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Racer
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From: corvallis or
Originally Posted by Nathan Plemons
If and only if it's leaded gasoline. If it was leaded he would already know it because he would be asking us why his car wasn't running hardly at all.
Truth be known you want to run the LOWEST octane fuel you can while maintaining full spark advance under the worst conditions. Running a higher octane fuel than you need costs you horsepower and fuel economy. Some people will argue against this until they are blue in the face but the fact of the matter is that they are wrong, period.
If anybody claims a horsepower increase, ask them for the dyno chart or ask to see their timeslips. If they claim better fuel economy ask them to see their detailed long term records. I assure you that they will not be able to produce either. People like to think that because it costs more, it must be better.
Truth be known you want to run the LOWEST octane fuel you can while maintaining full spark advance under the worst conditions. Running a higher octane fuel than you need costs you horsepower and fuel economy. Some people will argue against this until they are blue in the face but the fact of the matter is that they are wrong, period.
If anybody claims a horsepower increase, ask them for the dyno chart or ask to see their timeslips. If they claim better fuel economy ask them to see their detailed long term records. I assure you that they will not be able to produce either. People like to think that because it costs more, it must be better.
Team Owner
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St. Jude Donor '10
Originally Posted by VictorRussell'92
I gotta ask why?
If youre not running turbos, supercharger, or nitrous...chances are you don't need high octane fuel. Unless of course your compression ratio is 13:1 or something like that.
Race Director
Joined: Sep 2000
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From: The Top of Utah
Originally Posted by Nathan Plemons
Truth be known you want to run the LOWEST octane fuel you can while maintaining full spark advance under the worst conditions. Running a higher octane fuel than you need costs you horsepower and fuel economy. Some people will argue against this until they are blue in the face but the fact of the matter is that they are wrong, period.
And drain your wallet, while HURTING performance.
Of course there is the SOTP effect. If the job was difficult enough and/or cost enough, it will FEEL faster. Same as why your car always runs better after you wash it.
RACE ON!!!
Thread Starter
Instructor
Joined: Oct 2004
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From: OKC Ok
alright thanks, alot of good information. 
I'll say forget 101 then. I just wasn't for sure, I had some guy tell me in his stock gt stang that he could gain like 3 tenths of a second by using higher octance, that I could hardly believe, plus he would never show timeslips, oh well, mabey i'll forward this to him. Thanks again...
I'll say forget 101 then. I just wasn't for sure, I had some guy tell me in his stock gt stang that he could gain like 3 tenths of a second by using higher octance, that I could hardly believe, plus he would never show timeslips, oh well, mabey i'll forward this to him. Thanks again...
Team Owner
Joined: Oct 2004
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From: altered state
St. Jude Donor '05
Not your fault. Consider the source. The guy still plays with horsies! And ya can't get 30 of them in a can, unless its pressurized and sits in pretty blue bottle tucked out of sight...
Le Mans Master
Joined: Mar 2004
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From: Ft. Lauderdale Fl
Don't waist your.....
Don't waist your money. Your computer will automatically lower the effect of the higher octane. Your best bet is to use a premium mid level octane like 89-92. If you want to go faster, you usually can't get it in a bottle.
Team Owner
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From: I'm the walkin dude I can see all of the world...
St. Jude Donor '03
Originally Posted by SurfnSun
The higher the octane level the slower the fuel burns. Higher compression make things burn faster. Low compression + slow burning fuel = a dog.
If youre not running turbos, supercharger, or nitrous...chances are you don't need high octane fuel. Unless of course your compression ratio is 13:1 or something like that.
If youre not running turbos, supercharger, or nitrous...chances are you don't need high octane fuel. Unless of course your compression ratio is 13:1 or something like that.
Thank you. I am now smarter from reading your post. 
Drifting
Joined: Mar 1999
Posts: 1,931
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From: Norcross GA
The higher the octane: the slower it burns, leaves more carbon behind, and makes fewer BTU's, has fewer more-volitale-compounds, less prone to lighing off. You should only run as much octane as needed, any more and you are wasting $ and producing less power.
Higher compression helps the charge burn faster (same as more charge in a smaller box).
Higher compression helps the charge burn faster (same as more charge in a smaller box).
Safety Car
Joined: Sep 2004
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From: Port Orange Florida
If I could find 90 around here that's all I run.ALWAYS run the least octane you can without detonation...er pinging...My 4.3 Blazer loves 87..93 chokes it.
The vette is okay with 89 but 92 gets a touch sluggish when fully warm. 90 would be my gamble here.
The vette is okay with 89 but 92 gets a touch sluggish when fully warm.
90 would be my gamble here.