So, I've been running 37s (37 X12.50R17 LT) on my 2017 JK Recon edition (xtra .5" body lift from factory) on 3.5" Metalcloak Game Changer suspension. I've done most of the required (suggested?) changes that come with adding 37s, and I've been very happy with my Milestar Patagonia M/Ts. Since I bought the lift, I've added weight (winch, aluminum oil pan skid, and carry more safety tools than I did originaly) and the Jeep came with steel f&r bumpers. I have the Mopar High-top Fender flares and Hyline aluminum fender liners. I've permanently take out the back seat for weight reduction. Zero rub with the 37s regardless of flex or droop, and as I've mentioned been very happy with the setup.

So here's the question. I need to replace the tires, and I want to go with 38s (38 X 13.50R17 Milestars). That's basically adding .5 inch on top and on bottom and .5 inch on each side. Since I've added the weight I have and (knowing the drill) will likely add more weight over time. I'm toying with the idea of replacing the 3.5" MC springs with 4.5" MC springs (2 door versions) due to the addded weight and minimal tire size difference. Should I go that route or just go with the 4 door version of the 3.5" springs?

Any help is appreciated.

 

The Recon doesn't come with an extra 1/2" body lift, they come with a stiffer/ taller coil from the factory. You've got the same 3.5" that everyone does. Do you have a need to bump to 38's with the extra width? As you mention, you're really only gaining 1/2" and there's a lot more beef to handle for that little bit of lift. A friend ran 37x13.5" coopers and while they're noticeably larger than the 12.5" tire, it probably wasn't worth it. FWIW- he ran it on the Metalcloak 4.5" game changer (4dr with no weight, no bumpers), poison spider flares, and raceline beadlocks with 1.5" spidertrax.

I'm just trying to help back you off the ledge. If it's already too late and you're committed to 38's then you can ask me to leave.

 

My bad on the 1/2" body lift. I thought I read it somewhere, but I couldn't find it again so I'll cede that. The extra inch all around costs me only 10.4 pounds in weight per tire, but it also allows more tread on the ground with less of an air down netting more height over rocks and obstacles. So, yes it's 1/2" but it's actually more due to not having to lose well over an inch to get an extra inch in tread. This is most of the rationale.

 

Sounds like you are looking for someone to tell you to go to the 4.5" springs, so I will tell you, go for it. Have fun.

 

I think the logic you're using to justify the move to larger/wider tire just isn't going to translate to real-world differences of getting up over something or not. Additional tire weight (every 40lbs adds up, specially at the spinning corners when it comes to acceleration and deceleration) and raising the COG is only going to degrade the ride and off-camber wheelin situations. If it's just looks you're going for, go for it. I'd be hard pressed to see someone suggest these changes as positive.

 

Ok. You three have a lot of experienece and I appreciate your opinioins. Wasn't sold on the longer springs. I was just kicking around ideas. Must be a touchy subject I guess. I'm going to stick with the 3.5" springs due to the COG argument. As I mentioned, I was kicking around ideas (not expecting for three rapid fire kicks...) That said, I think I'm going to give the 38s a shot. If they work out, cool. If not, ok. I need new tires anyways and I'm going to give them a shot. It's probably not tremendously worse than a set of 37" Nittos or Mickeys at the same weight.

 

Keep in mind, 37’s are already a huge stressor for stock axles, now you’re putting 38x13.5’s... you really need to look seriously into a stronger set of axles or at least gusseting and trussing your front axle. Chromoly axle shafts will be needed soon too.

You would do well to listen to the advice everyone has given here. I’d stick with the 37’s if I were in your shoes.

 

As another perspective, I guess the one thing I keep going back to is the location. You're on an island. It's not like you'll be doing multi-day high speed freeway trips or anything, just round and round and round. What's the typical annual mileage on that jeep?

 

around 7k per year