Any one know this about tyers ?

If I have a 195 50 R15 what is the od of this ?

I am fitting 215 45 r 17 and looking to see if gearing is a problem .

this is on a type three automatic why I am asking , :party

well, 215/45/17 have an outside diameter (in inches) of 24.618, and a circumfrence of 77.340

a 195/50/15 has an OD of 22.677 and a Circ. of 71.242. Quite a big difference.

I have 215/40/17 which has OD of 23.772 and Circ. of 74.681

Hope that helps :thumb

I forgot to add that there's a 10% difference in the circ, so the speedo would also be out by 10%, but you knew that..

Thank you :beer


I see it will be better now with the subaru in the rear , as for the speedo I got a fix for that , in time I will show all 🙂

Um where did you find the numbers please ?

A while back someone posted an excel program which did all the conversions for you. I downloaded it, and i just put in your dimensions. It calculated the rest. I can email you the program if you like but I don't know how to put it up here.... send me your email address, it will be easier that way:thumband faster

[Edited on 16-9-2004 by Oasis]

If you go here http://www.tirerack.com/tires/SearchTires.jsp
and choose a tyre size and select the specs of one you like the look of it gives the circumferences. If you pick a common one it brings up a big chart with lots of sizes to compare.

Or http://www.mr2.com/FORMS/tire.html
for a comparison of tyre sizes, current size compared to new options with an allowable speedo error- quite a good calculator 🙂

Or this one http://www.blackcircles.com/home?source=menu
I haven't used, but have seen the link around.

Cheers
Jeremy

Thanks guy very helpfull

its not very hard to do an a calculator

say for a 195/50 r15

2 * (195 *0.50) +15 * 25.4

this is the same for any tire it gives you the od in millimeters though so to go back to inches just devide by 25.4

to give an indication a stock 165r15 has an od of 650 mm or 26 inches
marcel