help me...im dumb

[soceur]

http://www.newcelica.org/forums/showthread.php?s=&threadid=20511

its dead in there so i posted here

thanks

[Jesse IL]

Tire sizing is broken down into three numbers, separated by slashes or letters. For instance:
215/40ZR17
215 = section width, which is width of the tire in mm
40 = aspect ratio, which is a percentage. In this case it would mean the sidewall height (aspect ratio) is 40% or the section width. Actually, this percentage is a pretty rough estimate.
ZR = the Z is a speed rating and means tire is rated for constant speeds at 150+ MPH
17 = wheel diameter

Most tire manufacturers recommend the following rim widths for these section widths (assuming low profile tires). The rim is actually the outermost part of the wheel, most people just like to call wheels rims. You should note that as you go to smaller aspect ratios, usually the recommended rim width increases.

205...7.0" rim
215...7.5"
225...8.0"

You can usually go a 1/2" either way on these recommendations, but IMO, I would only go a 1/2" smaller. In other words, I wouldn't put a 215/40ZR17 tire on a 17x8 wheel, but would put it on a 17x7

Hope this all helps.