GT Mustangs

allnotch · 11-02-2008, 11:39 AM

This gas station down the road sells 100 octane fuel, it should be okay to run that in a stock 02 gt with boltons?

PureVenom · 11-02-2008, 12:06 PM

For what? A stock GT with bolt ons needs nothing more than 87...or 93 if you have a custom tune on it. Running 100 is just throwing money out the window for nothing and possible damaging your plugs and cats...and will actually cost you some power because it doesn't burn as fast as the lower octane and your car is not setup for it.

So, no, you really don't need 100 oct in a stock GT unless your boltons include a supercharger, turbo, or big shot of nitrous.

05RedDevil · 11-02-2008, 02:41 PM

+1

Herbstang · 11-03-2008, 12:37 PM

Like Rob said unless your tuned for it Don't use it your engine is designed to run at a specific compression ratio...generally higher performing engines will have higher compression ratios, which is why they require higher octane gas. Basic engines of the every day use car are designed to run with lower compression ratios, and thus have no problem running on lower octane gas. An engine designed for 87 octane gas should not knock if you have good ...truely 87 octane gas. Putting higher octane gas, such as 91 or 93 or whatever, does absolutely nothing to increase the performance of this engine. Many people mistakingly believe a car that usually uses 87 octane, will suddenly increase it's power and run much faster if you fill the tank with 93 octane or something. LOL...not true one bit. The only thing it does is increase their gas bill. As long as the gas you are using does not let your engine "knock" at all (due to pre-detonation), that rating gas is all you need.

05RedDevil · 11-03-2008, 04:26 PM

I wouldn't say not true at all. Some manufacturers have proven results of all the way up to a 3hp gain when rnning 93 as opposed to 87 octane. Woo. Maybe 3hp out of a V8 engine!

Scut95 · 11-03-2008, 06:12 PM

all the above not to mention you will get less MPG as well

Herbstang · 11-04-2008, 07:13 AM

Quote:

Originally Posted by 05RedDevil

I wouldn't say not true at all. Some manufacturers have proven results of all the way up to a 3hp gain when rnning 93 as opposed to 87 octane. Woo. Maybe 3hp out of a V8 engine!

I like to see those results !! higher octane fuel in and of itself does not improve performance or fuel economy. in fact it can be quite the opposite. higher octane fuel burns slower than lower octane fuels do to prevent detonation. running more octane than you need will cause more engine deposits to form, and that will cause a decrease in engine performance and fuel economy. use only the octane you need and no more.
A higher octane simply means it has a higher flash point meaning it takes more heat and compression to ignite the mixture.Octane boosters don’t really bump up the octane of the fuel Most only 3-7 points with is less then one octane level. Octane booster do however contain additives that remove or neutralize free radicals in the fuel that promote detonation and pre-ignition.
So to avoid igniting the a/f charge prematurely you want something that has a higher flash point. If your engine don't have any problems with the engine suffering from detonation or pre-ignition you don't have to worry about using a higher octane fuel. it won't do anything.

Additives or lack of, in the fuel can help to increase or decrease the burn rate slightly as well. Running a higher octane fuel in of itself will not increase HP. This is a myth. You wont get any more power because the compression doesnt change.
Rule of thumb is only run the amount of octane needed to prevent detonation or pre-ignition of the fuel. Run anything over that and there will be a loss in power as the fuel/air mixture is not able to burn completely.
Black smoke or carbon collecting in the exhaust tip is a sign of a rich mixture and/or the engine not being able to burn all of the fuel completely. Runnning a higher octane then the engine needs or was designed to run can and often will shorten the life of the polution control system (cat convertor and oxygen sensors)

slostang · 11-04-2008, 11:39 AM

You could see a little more HP with that fuel, it will allow the computer to use the max commanded timing, but it will probably be negligible. It all depends on how your tune is setup. Yes just running a higher octane fuel can increase your horsepower, it has been proven over and over again. But it usually has a lot to do with how your tune is setup and may not be using the max potential because the octane is not high enough. For example my tune commands 20 degrees of timing. On 97 octane it will maybe see 18 degrees, but with 106 octane it uses every bit of the timing that is commanded.