So I have done some research and I need you guys to help me check my thinking.

I am running 235/75/15 inch tires. According to what i found that means they are six inches taller than stock tires. According to the formula of 1 inch = .1 change in gearing, that means my final drive ratio has been changed by .6. So that has raised my gearing from 3.73 to 3.13. That would account for the loss of low end power in my rig. So I am thinking that if I change the gearing to 5.12 that should make my final drive ratio 4.52. That would be lowering the gearing .79 from stock. Should make a pretty good setup for mainly driving around town with the hopes of some occasional offroading in the summer.

Please feel free to chime in if my math is wrong or if I have completely botched the thinking. I am fairly new to this type of thing and my math sucks.

John

Yep, your math is a bit off.

Stock size on my Tracker was 195/75/15.  Diameter would be 26.51 in.  Circumference 83.28 in.  Revs per mile 784.6.

A 235/75/15 would be 28.87 in., 90.69 in., and 720.4.

So only 2.36 in. taller, but 7.41 in. bigger around.

Hope that helps.