tire sizes


New Member
i am upgrading my tires and wheels. i have 225/55/16 and i went to a dealer ship and they said i should put 225/40/18 on my 18X8. will that look that much different and should i have went up tire width or not


2002 Mustang
i would get pretty much the widest tire you could fit all the way around on those rims both front and back that way you can rotate them anytime you want and get a much better look all the way around


just say my name 3 times
225/40-18’s will actually make your speedometer read 2.6% too fast. When your speedometer reads 60mph, you’ll actually be traveling at 58.5mph…

i think the 245/40-18’s are the closest you can get with out altering the speedometer.

here, check out this tire calculator that will show you both side and end views in comparison to one size vs. another, plus what it does to the speedometer reading.


then stay away from the dealership with the idiots working there… research the facts, then you don’t have to trust the idiots… in fact, you’ll be able to educate them..!!

Mr. B :cool:

P.S. - just food for thought.... 275/35-18's really look beefy on the rear, how ever i think they rub up front on the pre '99's... but hey i would go 245's up front and 275's in the rear's... screw not being able to rotate... it's all about the look..!! :crazy: