nhmtns
11-25-2005, 02:44 PM
I'm trying to better understand tire size numbers.
I know the second number is an aspect ratio (height divided by the width). So will a 225/45 17 tire be about the same height as a 215/50 17 tire because the 225 is wider, or does the second number automatically determine which is taller? I think it depends on the two numbers, right?
225 x .45 = 101.25
215 x .50 = 107.5
If my math is correct, the difference should only be 6.25 mm which is marginal.
UkNuck
11-25-2005, 03:22 PM
If my math is correct, the difference should only be 6.25 mm which is marginal.
What you have calculated is the sidewall height - don't forget the difference in overall outer diameter is TWICE that (OD = rim diameter + 2 sidewalls).
Samurai Jack
11-25-2005, 03:36 PM
Look here. This will help you:
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=7¤tpage=33
waktasz
11-25-2005, 05:50 PM
I'm trying to better understand tire size numbers.
I know the second number is an aspect ratio (height divided by the width). So will a 225/45 17 tire be about the same height as a 215/50 17 tire because the 225 is wider, or does the second number automatically determine which is taller? I think it depends on the two numbers, right?
225 x .45 = 101.25
215 x .50 = 107.5
If my math is correct, the difference should only be 6.25 mm which is marginal.
With the WRX I always would want to err on the side of the shorter gearing. The 215 would be a decent amount taller (2% according to miata tire size calculator) and provide less grip (skinnier tire and taller sidewall) Stick with the 225. Or 235/40 :)!!!!
nhmtns
11-25-2005, 09:39 PM
With the WRX I always would want to err on the side of the shorter gearing. The 215 would be a decent amount taller (2% according to miata tire size calculator) and provide less grip (skinnier tire and taller sidewall) Stick with the 225. Or 235/40 :)!!!!
Well, usually wider = better grip, but definitely not in snow!