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Old 02-15-2016, 11:30 AM   #4
Tectoniic
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Quote:
Originally Posted by go_a_way1 View Post
why is the width effecting the speedo? 225 and 235 should have the same diameter all other things being equal (ie 40R/18). honestly go 235 if thats the look you want.
The width affects the diameter. In 225/40/18 the 40 is not the height of the sidewall it is the ratio of the sidewall to the width of the tire.

225 x .40 (think of it as the height of the sidewall is 40% of the width) = 90

235 x .40 = 94

The 235 is ever so slightly taller.
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