I run 4.88s with true 37s and its almost to low geared for a dd. Wish i would of went 4.56 i have a 6spd.

 

Ours is a 6sp as well and we still have the 4.10's. It is painfully slow but the fuel mileage makes up for it since it is a daily driver. The rubi transfer case helps out here and keeps the low range workable. Overall very impressed with the 19-20mpg after the lift and tires, 4"/37's. Yes, "I drive miss Daisy". To be honest the 37's no longer look large or even oversize, they simply seem to be proportional. The rear pinch seem does need to bent or cut, took about 10min per side and of the course the fenders have to be trimmed in some manner. My wife wanted to keep a close to stock look so our fenders appear stock from the outside, all of the trimming is on the inside and we have only very minor rub when disconected at full turn and stuff.
Mike

 

Stuffs pretty well for full fenders. Trimmed about an inch from the back of the bumper as well. The inside lip of the fender is trimmed off (easy to do with just a razor blade), tough to tell it's even gone from the outside.

 

37s fit a 4 door perfect, They should have came from the factory with the 315/70/17.

Some pics for you
2.5" lift 315/70/17- 34.4" 3:73s

Same lift and gears drove it for 25,000 miles till i traded it in, Cut fenders added 37s huge difference at first but like miked said it looks proportional.

 

I run a 6spd. W/ 4.88 and 37's

Love everyday I drive it!

 

Same here!! 4.88s are perfect for a MANUAL trans JK with 37's. If you have an auto from what I've read then go with 5.13s. Like was previously posted, plenty of people regretting going with 35's. If you are going to regear and even think about 37's then plan for it. I can tell you, the 37's look huge for about a month...then it just looks 'normal'.

 

Go with the 37" km2's, I did from stock rubi tires. U will be glad that u did, cuz if u have 35's and u see a jk in person on 37's u would have wished u got 37's instead. I parked next to WOL's jk Moby which is on 40's and I already want 40's now lol

 

why do you say its a pinino grenade? due to the gear being so small? wouldn't a quaility gear and pinion handle it just fine?

 

Thanks for your opinions.

I guess I should have mentioned I have a 2012 Rubicon with 4.10 gearing, so I can run 35's BFGs KM2s stock. (the stock Jeep on 4.10s seems a little low geared with stock tires compared to the 2008 Rubicon with 4.10 on stock tire that I had before trading).

I will be putting on a Teraflex 3" Elite LCG Long Arm and already have Bushwacker Flares brand new in the box that I never installed on the 2008 Rubicon, or I'm considering the aluminum flares powder coated white to match the Jeep.

I will completely skid up the Jeep with a complete set of Rockhard skid plates, AEV Nth Degree rear diff skid, lower control arm skids, & Riddler diff covers and also doing a steering stabilizer relocation. I plan on running argent Pintlers. I don not plan on doing any engine or exhaust mods. The Jeep is a daily driver for the wife. (who is already not happy that I am putting a 3" lift on it as she will have to climb in to go to Walmart)

I don't plan on any really hard trails like Prichard, I use my 4x4 ATV for my harder/extreme four wheeling (easier to roll back over :P ) My type of trails is moderate 4 wheeling on rocky Southwestern Trails. The worst trails I intend to go on would be something like Poison Spider Mesa - Gold Bar Rim - Golden Spike or Moab Rim or Cliffhanger in Moab this October and I'm planning a Rubicon trip in 2014 (doing the bypasses when possible).

I'm not doing this for looks either, but for practical performance use while on the trail.

That is why I'm asking if the extra 1" is really worth the cost of re-gearing and the added expense for the larger tire for actual wheeling?

I took my 2008 Rubicon with no lift & stock tires on some harder trails in Az (Upper Woodpecker, Hackberry, Terminator, Log Corral, Coke Ovens for example) with little issues except the few times I high centered and had to be pulled off (the skids cane in handy). A 3" lift would have prevented the high centering. There is only so much you can do with a stock Rubicon. I posted a link to some photos of some moderate trails I've done with my old Rubicon in Az.

Hackbery Creek Jeep Run --- 01-09-2011 pictures by azsandrider - Photobucket

OR

Upper Woodpecker near Florence Az --- 12-11-2010 pictures by azsandrider - Photobucket

 

I'm running a 2012 sport auto with 35's on 3.21 gears..... I honestly doubt I will have to regear with 37's next year.... MORE THan enough power for the 35's!

I drag raced a ford CVPI at my last department and smoked it in the 1/4.

No gears for me!! Love my 2012!!!
(traded my 11 for it)