I was looking at some race car specs. The wheels were listed as 17x9, but the tires were listed as 24/61-17. What system of measurement is this? For the sake of comparison, how do I convert that to the usual 2xx/yyR17?

Thanks.

 

Try this:

(section width in centimeters) / (diameter in centimeters) - (rim diameter in inches):

24/61-17:

(9.45" section width) / (24.02" diameter) - (17" wheels)

 

Thanks. That helps. I didn't know what the numbers in racing wheel notation represented.

I took the above and solved for aspect ratio. So in normal tire notation, the tire is a 240/37R17.

Cool, and weird.