So at 70 I think I'm at around 2200. The gear table on here shows with 3.73 I should be at like 2000 or 2100. I'm over that for sure. I bought my jeep used and I have my procal set at 3.73. Any chance that could be set and still run a 4.10 gear? I wouldn't think so, but if so I need to change my procal!! Any insight would be helpful!!

 

Jack one tire off the ground.
Rotate it by hand exactly 2 revolutions while counting the drive shaft turns.
That number will be your gear ratio.

 

I was looking for the easy answer!!! Haha I guess I'll just have to do it.

 

Using mfg's spec'd tire height instead of actual measured height?

 

Well I know my tire height is dialed in on my procal. I went through a few different GPS and radar signs and its on the money every time.

 

So you haven't measured, correct? And you don't actually know which gears are installed? If either of those are different than what you 'think' they are ...

 

Correct and correct

 

what size tires? those rpms at 70mph look close to what I was seeing in a 2012 jk with 3.73's and stock 255/75-17 tires. my 2013 jku with 285/75-16's show 2000rpm at 70mph with speedo spot on via procal and gps.

 

35" nitto trail grappler mt