depends on whats done to your car, if its still mostly stock your not gonna gain much. better off just advancing the timing. but if you have mods like cam/intake/heads/full exhaust you would really benefit from a custom tune. if you like to do things yourself look into a tweecer. if you wanna leave it up to the pro's check around for local tuners and see what they use. SCT seems to be the leader in custom chips right now
I'm with Joe on this one. There is no "best" chip for your car that's readily available. The best one is custom burned to your application while testing on the dyno to get the best performance. On a stock engine, there isn't much power to be had with a custom tune, although I'm sure Ford did leave some on the table in favor of emissions and drivability when they built these cars.
ok...i plan on keeping the stock intake, but going with an e303 cam, mac or bbk headers, smog delete, 75mm throttle body, heat spacer....not to sure what else, maybe a supercharger...
If you were to optimize the spark/fuel tables and a few other major things like kill the tip in retard, etc, you would definitely feel the difference on a stock Stang.
Prob with doing that is the gain vs the cost of Self Tuning interface or Pro burned chip.
Now if you had plans to self tune ...................
That would be different as you were gonna buy the equipment anyway.
A Pro burned chip will become obsolete as the combo progresses from stock to something like h/c/i.
A chip you find off the shelf ..................
Not gonna say it won't give a gain but ...............
Not as much as a custom tune by the two methods above.