View Single Post
Old 12-01-2010, 04:10 PM   #23
Registered User
Join Date: Oct 2009
Location: Massachusetts
Posts: 585
My Ride: hates A/C & Sunroofs
Originally Posted by DangerousMind View Post
The 40 is the sidewall aspect ratio, which is a percentage of the width in cm. A 225/40 is 225cm wide and the sidewall height is 40% of 225, or 90cm. A 255/35 is 255cm wide and the sidewall height is 35% of 255, or 89.25cm. A 255/40 would have a sidewall height of 102cm, resulting in a 1" taller tire and some serious rubbing issues with that width. 255/35/18 all around is the correct combo
Thank you, I understand now.

Originally Posted by Penguin Koolaid View Post

You realize the second number is a ratio of the tire width.

225/40 = 90mm
255/35 = 89.25mm

255/40 = 102mm

That's why. You want to track your car and you don't even know the basics on how to read tire sizes?
Sorry, completely forgot it was a ratio rather than a measurement. I never quite understood the second number. I do and have known what the first and third numbers mean, my bad. Should have gone and looked. /thread

Last edited by MasterC17; 12-09-2010 at 03:21 PM.
MasterC17 is offline   Reply With Quote