[PowerShiftz02GT]

Does anyone know what the 2002 GT manual says what recommend gas to use? 87 or 93

Ive been putting in 87. I thought only the cobras are suppose to use 93. and what do you guys use and what is the advantages of using 93?

[RAGEman]

I can't remember exactly what it says, but I know it says 87 is recommended. 89 or 93 is optional.

[mustangmanic]

87 octane. No advantages with 93, unless u have a tune for it

[HMUSN]

^ exactly.

use regular

[Mustang RacR94]

of course theres a benefit to running higher octane, tune or no tune is easer to combust, longer plug life, its overall better for your internals as well, can lead to a cleaner engine to

[HMUSN]

Simply put, the octane rating of a fuel determines the propensity to explode
rather than simply burn when mixed with air and ignited. Exploding is bad.
Burning is good. The higher the octane, the more resistant to exploding.

If you are running too low of an octane for your motor, you will get
pinging. Pinging in its extreme form is also known as detonation. The
fuel/air mixture is igniting all at once and exploding instead of igniting
as a flame wave. The resultant "bang" is very hard on the pistons, head,
rods, and cranks. I've seen bent rods, cracked heads, pounded-out crank
bearings, cracked piston skirts, and chainsawed crankcases (*really* bad
thrown rods!).

In an overly-simplistic nutshell (sorry JC!), chipping a motor will usually
advance the ignition timing, adjust the fuel/air ratio, and modify several
other highly proprietary and secret things to increase performance. Among
the main factors in detonation are (1) heat; (2) compression ratio; (3)
octane rating; (4) fuel/air ratio; (5) ignition timing. Modifying any of
these factors can either increase or decrease the propensity to detonate.
Advance the ignition timing and you increase the potential to detonate.
Retard the timing and you decrease the potential to detonate. You can
balance these factors by modifying some to offset others. If you increase
the fuel/air ratio and advance the timing, you can raise the octane and end
up with more-or-less the same propensity to detonate as the non-modified
motor. Alternately, you could lower the compression ratio, but this would
cause a loss of horsepower and efficiency and undo all the gains of
modifying the mix and the timing.



run what it says to from the factory unless you have a tune for it.

[PowerShiftz02GT]

OK thanks guys.

[HMUSN]

yup

[johnr2001]

unless you advance your timing premium really has no benefits.

[AndrewA.]

I alwasy ran reg. but every now and than i use to treat her to some good ol expensive gas.

Than the tune came and now all she wants is that expensive stuff

[Paulnhbtx]

I have the same car as you color, rims and... Dammit I have been using 93 this whole time.... was it a waste of money? I had a 87 GT and put reg gas and it knocked

[Mustang RacR94]

i never reccomend regular octane in any kind of performance car, its a high winding 4.6 modular motor ive always put 93 in everything i own, then again i do take 4 hours at least once a week to wash wax and and detail my mach, and i did the same for my v6 before i garaged it, as well as my 81 Z28

[00gtCoolGuy]

are GT's performance cars? lol

[sk8flip67]

With anything higher than 87 octane you have to watch out for additives. I think but not 100% sure that shell (i know there are/were several gas stations) adds or at least use to add some compound to their higher octane gasses. Cant remember their logic but long story short engines got messed up. The additives were eating away at the metal in the engine and other stuff. That may not be waht happened but i know for a fact that the additives casued engine problems and reduced life. Heard it from a mechanic about a year ago debating about whether 93 was worth the extra 30 cents at the time and also read it on a news website back then. Its not much help without the specific details, but id research what additives the gas station you use puts in their higher octane gas and search online and see if those were the additives that were destroying engines.

[brianm]

i think shell had a prob with messing up fuel pumps on some cars, i forget which cars it affected. btw shell 91 is all i run

[Blk01ponyGT]

Originally Posted by 00gtCoolGuy are GT's performance cars? lol

yeah dude. hah. they arent that bad