Ok, my stocks are 275/60R20, my stock tune says tire size is 31.50. According to a post i found, that tire i have is a 33. I want to have an accurate speedo, and mileage on OD, what are you guys opinion, am i being ocd for nothing? Lol

 

Not at all, you absolutely want to be as accurate as possible. That tire size exact measurement is 32.99 tall, 10.83 wide and gets 611.3 revolutions per mile. Hope this helps.

 

yes it does help thanks!

 

Make sure you use the specs from your specific tire brand. My goodyears are 33" x 11" and 634 revs per mile which are different then above.

 

How did you come up with that?

 

Straight from the manufacturer's spec sheet. Due to stiffer sidewalls, different construction, etc. every tire is a little different even though they are listed the same size.