Can replace my 19" wheels with 17 or 18"? It came with the performance package that has 19" wheels.
In a world where every one is going at least +1 or +2 you are trying to be different and go -1 or -2? Why is this, winter tires?....and do you understand that some automotive engineer calculated the circumference of the 19"s into your perf pkg and this design choice is closely associated, connected to the gearing settings, speedometer, odometer, traction control, and torque? I do not recommend it but if you must and do not believe the engineers know best go here: http://tires.about.com/od/understanding_tires/a/Plus-And-Minus-Sizing.htm
it's unusual, but you can do it. you need to use taller tires to keep the overall diameter the same. and you need to make sure the new tires have the same speed rating or higher than the factory ones.
You will also have to check if it came with bigger rotors. Bigger performance rotors may not fit with a 17" wheel.
MM66 Good point! I see no benefit or gain performance wise in downsizing a big wheel part of a factory perf pkg. It would be like taking an L-82 with Gymkhana suspension to Sears and replacing the EOM shock absorbers with plain Monroes?
For what's worth, some standard OEM tire/rim sizes on Mustangs are as follows. P255/60HR17 = 29" Dia --- P215/65TR17 = 28" Dia --- (Base GT) P235/50ZR18 = 27.3" Dia ---(V6 w/Perf Pack - P255/40R19 = 27" Dia So it might surprise a few people that the 19" wheel option actually has the smallest Diameter.
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