I want to preface my response by admitting that I am a Supra biggot99YellowStang said:What would be best tire size for handling as well as wheel size, I saw some rims i like and they come in 18x8s and 18x10s as well as 17x8s and 17x10s, what is better for handling 17s or 18s? and what tire sizes for the 17 or 18 inch rims?
-> Mustangs don't handle! You need IRS (independent rear suspension) for that!
That off my chest, the more rubber you have on the ground (in general) the better. Also, the shorter the sidewall, the better for handling. Next, the compound of rubber that you run has at least (if not more) of an effect than the width of your tire. Lastly, the width of your tire should match the weight distribution of your car and the stiffness of your suspension. Admittedly, I am unfamiliar with the weight distribution of a rust...er...mustang. On a Supra (this is Supraforums, is it not), some (roadracers) have said that the ideal combination is 285 rubber on 18x10" rims up front and 315 rubber on 17x11.5" rims in the back. This assumes that you have appropriate suspension on that Supra to match the rubber.