After looking at the specs for these two tires they're close in weight.

Kumho:Size-37x13.5R22, OD-36.8 Weight-79.4lbs
Toyo: Size-35x12.5R22, OD-35 Weight-80.5

The Toyo is actually a lb heavier, but almost 2" shorter. So my question is how do you regear for the 37" Kumho's? Do you go 4:88 b/c it measures 36.8or 4:56 b/c it weighs the same as a 35" tire?

 

Thats a good question. I would think you would gear them to their weight. Cause thats what causes the stress on parts is the extra weight.

 

My truck is in the shop right now getting 4.88 in the rear.

 

37's normally require 4:88's, but since the Kumho's are lighter than most; 4:88's may be to much. The Kumho 37's are 11lbs/tire lighter than the Toyo 37s. The Toyo 38x13.5R20 are 100.3 lbs/tire.

 

I'd go with the 4.88's.

 

Weight has to be considered, but the rolling radius is what determines you're actually "final drive ratio". That being said, IMHO, the weight will have far less effect on gearing than the diameter. You're not actually carrying that weight, but you are directly turning that extra radius.

David

 

3.73 works for me ...for now. lol

 

I would agree.The size of the tire plays a large part in the correct final drive ratio.Turn a 3.55 into a 3.08 by adding a 35" tall tire.Gear for the tire size you want to run.

 

i'd go with 4.88's either way. its only gunna be a few hundred rpm difference from 4.56's and its worth the extra low end power/ acceleration in my opinion. also if you ever decide to go with something bigger then 37's or just a heavier tire you'll be covered.

 

a user has the 37x22 khumos for sale on her. he has 2 of them brand new for a rediculous low price. my brothre had that exact size. they were bad ***.