Diablosport Forums

http://www.gordon-glasgow.org/tirecalc.html

or, use this handy tire revs per mile calculator:

I run staggered tire sizes; I assume I should use the tire size info from my rear tires for this calculation...am I correct?

Thanks,
-Chris

Yes, the rear tires are the ones you use.

There are all kinds of apps for smart phones too..

thank you!!!

These calculations will get you in the ballpark. However, it has been my experience that your speedometer will be off by about 5 mph @ 80mph. I used my GPS to help me fine tune the value for the revs per mile in the tune. I ended up having to use a value of 880 revs per mile for a set of 275/40 R18 wheels. If you run this through your calculations it will tell you that you should be running 756 for the revs per mile.

I'm trying to do the tire Change on my truck and was wondering do I put in the revs per mile in the tire circumference? I'm running a 35x12.50x20.

sup bruh ,im tried to recalibrate my speedo but it asked for diameter and mine says is 100.25 for a set of 275/55/20 lowest value is 500 what im doing wrong