sorry all but could some1 just quickly explain to me what the middle number for tire measurements mean? eg. the 40 in the 225/40/18.

and also, what's offset??

thanks all.

 

225/40/17 first number is the tire width...second number is the tire height ...third number is the interior diameter of the tire or the wheel size the tire is goin on. the higher the numbers the bigger the width or the tire profile ect ect ect.

 

The middle number is the aspect ratio used to determine sidewall height. For example, 225/40/17 translates into a 17" tire that's 225 mm wide, and the sidewall height (90mm) is 40% of the tire width. 40% of 225mm = 90mm.

 

Click below so you can read about the info. BTW, that's not a stupid question. :o



Offset
Section Height