I believe my profile is current (can't easily see it on my iPad right now) but just in case, I have a 2009 JKU Rubicon 6 SPEED, full traction 3 inch lift, bilstein 5100, lower front adj control arms, adjustable front track bar, EVO Draglink flip (not installed yet), k&n drop in, Dynomax rock crawler exhaust and a superchips. It's now time for some wheels and tires. This is my daily driver (5 mile commute to work). I never considered anything smaller than 35's but in looking at countless pictures here in various threads, seems like 37's look better on the JKU. The price difference between the two is about $50 and not a factor for me. I don't do any hardcore offloading. Mostly dirt trails here in the southwest. I will get EVO c gussets regardless of which size I select. Rear tire carrier to replace stock is on the list as well. I will trim the rubi rails and do the pinch seam regardless of which size I select. The only issue that stands out is gears. Some say I might be ok with 4.10's and 35's but realize I would have to regear for sure with 37's. Am I missing something?

I also read in another thread (jpop I believe?) that suggested I get 18's for 37's. Thoughts on this? I've pretty much decided on Nitto Trail Grapplers. Still undecided on which wheels.

Thanks

 

To further explain the reasoning that Jpop brought up about 18"... if you look at the max load weight and load range on a 37 with a 17 vs 18, there is a big difference. It would be ideal to run a 37x13.50 on a 18" but not all of us can swing tires and wheels at the same time...

37x13.50R-17LT Black Sidewall Load Range = E Max Load = 4300lbs. Tread Depth = 21/32 Overall Diameter = 37.1

37x13.50R-18LT Black Sidewall Load Range = D Max Load = 3860lbs. Tread Depth = 21/32 Overall Diameter = 37.0

 

This is specific to the Toyo/Nitto 37s as they share the same carcass. With other manufacturers there might not be this large of a difference or other alternatives. It's not a case of 18s being the prescribed wheel for 37s as opposed to 17s, just from these manufacturers the rigidity of the sidewalls are better suited for the vehicle in the 18x37s.

 

i cant say anything about the wheel sizes.. but i can say that you are probably going to want to regear to 4.88 or 5.13 regardless of what tire size you go.

 

I don't think you can go wrong either way. I can say that you will be very happy with the trail grapplers. I don't think the 4.10's would be horrible with the 35's being you have a 6 speed, but 37's will definitely need more

 

Thanks for the better explanation/wording...

 

Digging up the detail on the 2 tires was more important, just didn't want anyone to think I had something against 17s.

 

True!

 

Just my $.02,

I have a 11 jku Rubicon (4.10) with a 2" bb, cut pinch seam, and flat fenders. It is my dd for my commute of about 24 miles. About 4 months ago I put on GY MTR's in the 37" flavor.
Mine is an automatic. I'm not really sure why everyone is saying you must regear. Either i got an extremely strong 3.8 or maybe a tranny with an extra gear, or maybe ???, but anyhow,
my rig has plenty of power around town, and cruises on the highway at 70 no problem. When i need to pass or come to a steep hill it may drop a gear, but only if i really put my foot into it.
From what i have heard, some of it is an issue with cruise control, but I don't use it much so I can't rightfully say.

 

Just my opinion, but I've got a 2007 JKU with 35's right now and think it looks perfect. And if you won't be hitting any big rocks, I see no reason to go any bigger.

Now, as for gears, my last JK was a 2 door with the 6 speed and I had 35's on it too and was pretty happy with the gearing. Around town it was great and I used 6th all the time doing 50 mph or so. Once you hit overpasses on the highway, I would either downshift to 5th or lose 5 mph.

Hope that helps some!