Which octane is best to use?

sterlinator · 10-05-2002

the book recommends 87 octane for my 02 gt, but i live at 5500 feet above sea level, should i increase?

Twister · 10-05-2002

you should use the octane that gives you the best milage and the lowest that will not make the engine knock...I use 91 octane since it gives me the best milage, I wish So-Cal still had 93, I had great milage then.

Vortex · 10-05-2002

Most places you can get away with 89 (or equivalent) on my car at sea-level in FLorida on a hot day....normal day, I can run 89 just fine but if i get on it, it pings, .. you have to experiment, but i would stay at least 89 or up... 87 isnt enough for that motor.

jasons99gt · 10-23-2002

Vortex,

I certainly dont want to undermine your expertise, but I just wanted to share that I've been running 87 octane on my 99 gt for the past 2 years and I'm getting 18.5mpg city/24 highway.

Thanks,
Jason

Vortex · 10-23-2002

dont worry, lol, i dont claim to know it all. with everything ive been thru, thats been the case. If you can run it, even better.
Have you tried running 89 or even premium in it yet? sometimes its worth the extra 10 cents per gallon.
I guess it all depends on where you live. sea-level, moderatly warm day, 89 doesnt even seem to be enough.
I get 20mpg... arent the newer cars better on gas?

95justang · 10-23-2002

There must be something wrong with my car because I run 93 octane and still only get about 17 MPG. When I drive in stop and go I get about 13. What could be wrong with my car?

Vortex · 10-23-2002

do you get on it a lot?
when was the last time you did a tune-up?

Anthony Damato · 10-27-2002

I run 93 and sometimes 94 in my 85GT that I have done a lot of mods to, and I know that my mpg sucks, but we all know that we didn't buy a mustang for its gas mileage especially if you have or have plans for mods

You should do what everyone else told you to do. Just test out the octangs. You might get better milege out of the lower octangs, but you'll get a lot more performance out of the higher octangs. And that my friends is what these cars are all about.

Anthony

View My Profile! · 10-31-2002

I believe my dad also ran 87 in his '01 GT. I run 87 in my 5.0.