Good Morning:
I am trying to decided between 35 or 37 KO2's. I have a 2013 JKUR, manual, with RK 2.5 lift with all the Arms... Guess it is called the X-factor now..... Fender flares, artec armor, and am currently running the BFG KO 35's. I was looking at the specs and the weight of the 37's is not much more then the 35's and the 37 is not a true 37. I don't want to change gears or do any other modifications at this time. What are your thoughts on the stock gearing and other issues that may arise with the 37's vs the 35's. I am thinking because the weight is less that what a Nitto MT would be that I would be fine but not sure about the other issues to take into consideration. My Jeep is a daily driver that does see trail use on the weekends. Thanks in advance. Here are the specs.

Size Diameter Width Rim Range Measured Rim Tread Depth Load Range Max Load Max psi Weight Revs/Mile
LT 35X12.50R17 34.5" 12.5" 8.5-11" 10" 15/32" E 3195 lbs 65 psi 66.5 lbs 602

LT 37X12.50R17 36.5" 12.5" 8.5-11" 10" 15/32" D 3525 lbs 50 psi 71.3 lbs 569

 

Do it and dont look back

 

What are your gears now? I have the 315/70r17 ko2's(few pounds lighter than the 35's) with the 3.8L, 4.10's and auto. It is not bad around town/ freeway but I do have to run higher rpm's up hills. I wouldn't want 37's without gears. I'd bet your 3.6 wouldn't be bad with 35's if you have 4.10's.

 

Go Big or Go Home

 

If you have the factory 4.10s I wouldn't go above the 35s--that's already pushing it.

If you have the 3.73s, you'd want to focus on regearing anyway.

 

Go 37's you will not be happy until you do. I think 37's are big enough to break stuff but you won't need 60's to run them. I'd love some 42's but my wallet says "No" also the wife says "No" too. I'm happy with the performance of 37's.

 

I have the 3.6l with 410 gears. Right now with 35s I have no problems doing 70-80 up the mountain passes pulling a small trailer. It's not a true 37 and is lighter then a lot of 35s that is why I was thinking I would be okay. Thanks

 

Are your fenders flares flat or at least cut? At 2.5" your clearances for 37's MIT be tight. Ruby rails and pinch seam cutting would open up the wheel wells a bit, especially in the rear. Stubby front bumper MIT be needed also. Will your current tire carrier hold the extra weight and accommodate the larger sized tire? You will need a hi lift or wood blocks at the very least as well, since most scissor jacks won't be enough to raise a 37.

 

Also... do you like your tie rod, drag link and steering? If so, I'd be worried about those too.

 

2012 manual 35's that measure out at 34 with the 3.6 and 4.10's its not bad but you can feel the power loss. Gotta put your foot in it on rolling hills and inclines going to 4.56 soon. 37's would need a regear imo.