on my 96 gt owners manuel it says to use 87. now some of my friends say its better to use what the engine is made for and other friends say the 93 is better for the motor. i'm going to the track soon and i want to know what gas will my motor run best on at the track andon the street. its a stockmotor with intake, wires, and udp's.

 

you will have a slight power gain using 93 (2-3hp)but it will not hurt your engine at all by using 87 unless you advance your timing.

 

87 is what its meant for unless you have a oct specific tune it wont be worth it in costs and it may not even run right.

 

stick with the 87.

 

i'm getting ready to do the pi swap and i know my compression will increase so will i have to go up in octane.

 

Not true. With stock timing, 87 will give the best performance. 93 will do NOTHING.

 

93 octane is more likely to take a little power due to the additives causing a build-up of deposits on the combustion chamber and the backs of the intake valves.
Don't waste your money on more expensive gas until you have a tune that requires it.The dyno will tell you when by showing a slight loss of power when the detonation begins that wasn't there before the timing was advanced.
If your engine pings with stock timing then there's something wrong with your engine.Either it running too lean or the combustion chambers have a carbon build-up that's causing the problem.This can happen by raising the compression ratio or by actually having glowing carbon embers setting off the gas.

 

Run the gas that yeilds the best mileage. 87 octane from Shell won't act the same as 87 from BP, Philips, Conoco, etc. See what your car likes best, and go from there.

Mine happens to like a mix of 91 octane from Shell and Philips 66 (I just alternate which one I go to).

 

i use 89, but only cause it's cheaper here. but as fortrack day,stick with 87. with your mods higher octane won'tdo a thing.

 

my 03 stang runs better with 87 octane, with and higher it doesnt sound as good and has a slower pick up it seems, ps dont use grocery store gas (kroger heb randalls) the best preformance ive noticed is with 87 exxon or chevron gas (the stuff with tchron) thats all i use, i can be a few cents more per gallon but i tihnk its worth it