Tire Sizes and calculations

15" 225x60x15 16" 215X60X16 17" 205X60X17

As for original tire size for your car, most likely an original E78X14, which would equate to a 205X70X14

Bill S.

elmo wrote:

Why does the width get skinnier as the wheel gets taller? Why couldn't you stick with the same width, just a shorter aspect ratio? like 225x45 17"?

Scott Williams

This site will show tire size comparisions with overlays and speedometer differences.

You would definitely need to switch to a lower aspect ratio. On a

235/60x14, your outside diameter would be 25.1 inches. To maintain that same OD, or close, using a 16" rim, you'd need to use a 235/50x16, which would give you a 25.25 inch OD. The same width tire in a 45 aspect ratio would be 24.3 inches OD, which would be too small. It's desirable to maintain the same OD in order to not affect your speedometer readings. The 0.15 inch difference in the 235/60x14 vs. the 235/50x16, would be negligible (slightly over 1/8 inch overall).

OK, so I was sorta right, even though my math sucks.

Scott Williams '66 HCS

You are correct,my original posting was done far too early in the AM, and without the benefit of any coffee first...............As you go up in rim diameter, the side wall aspect must come down..................

Bill S.

Scott Williams wrote:

Thanks for all your help, guys - looks like my Stangs gonna get some new booties for her sexy new rims!!

"Bill S." a écrit dans le message news: JSl4b.55099$ snipped-for-privacy@news4.srv.hcvlny.cv.net...