So diesel JLU? 4 door? but not a pickup?
The big question is what will you do with it?
Where will you go?
How much highway?
How long will the trips be?
33s/35s/37s/40s
Each choice reduces fuel economy, range.
Add airing down, each choice might increase capability, depending on use.
The bigger the tire, the higher the unsprung weight, the rougher the ride.
"I'm considering clearance, mechanical wear on the vehicle, availability of replacement tires after you use you spare"
Where are you going that you worry about getting a new tire? If that is a concern, buy a world wide available commercial tire, set yer rig up to work with that. AND guaranteed, if you go for a bigger than stock tire WILL increase mechanical wear, but beyond wear, even after regearing every big, bigger tire choice increases the likely hood of breakage. mechanical wear is .... a polite way of saying stranded.
I can agree with some of the concepts here, lest you think I just chase you around the forum to disagree anytime you suggest stock is best. There's a thin line between useful modding, and modding that in the long-run only hinders our efforts towards reliability. I think you asked the right questions (what/where/how will you go? - to sum them up). If the answer is groomed fireroads, or trails of similar difficulty then I can agree, a stock JLUR will be just fine. We all know Jeep has gangs of magazine (well, probably VLOG/YT people more than anything these days) run The Rubicon in bone-stock JL/JLU Rubicons and they just did it with the Gladiators too. However, if you watch the run it doesn't seem relaxing or easy on equipment at all:
From the very start you'll see (and hear) that stock the JTR will do The Rubicon, but it won't do it without dragging belly non-stop and some bumps on the body. Go ahead and skip to around 25:30 for the body damage they gathered from just one run.
IF (and that's a big, BIG, IF) a person intends to run trails like The Rubicon, or trails with similar obstacles there IS a sound case for modifying. While these things have pretty good skid-plates, rock-sliders etc. IMHO I'd rather not drag my belly through an entire trail (not exactly treading lightly either). You talk about wear and tear and the possibility for mechanical issues and being stranded - but running a trail that is right at, or above the ceiling of your vehicles capability also imparts a lot of wear, tear, damage and the potential for major mechanical issues. Yes, they're skidded up but how long are you going to run a vehicle the way they do in this vid before you do mangle a driveshaft on a just-right (wrong?) rock?
Anyway, I want to reiterate the "trails with similar obstacles" part. The Rubicon is far, far, FAR from "America's Hardest Rocky Trail" as TFLT put in their video title. There are tons of harder trails in the same part of the Sierras. The thing that makes The Rubicon "THE RUBICON" is that it's unrelenting, it's just like that the WHOLE way. There are, however, a zillion trails what might have one or two obstacles just as hard as the hardest necessary lines on The Rubicon. A lot of us want to run in places like the Sierras and explore trails we're not yet familiar with and not have to worry (as much) about coming up on an obstacle like that and having to turn around and back-track for hours.
On my last wheeling/camping (Overlanding?) trip we had a bone-stock XJ with us... and before the end of the ride he was on a donut. We got him through everything - so perhaps I'm making your case for you. But the point is the more built rigs in the group could just continue down the trail, not needing a spotter, not having to stack rocks, and not "stressing" about it while we had to constantly spot and stack for the stocker. It slows a trip way down, and while the challenge is neat the first few times at the end of the day it gets old and most everybody wants to be able to stay in their rig and get where we're going.
As for the JLU vs. truck part, I'll save that one for another day... I have TONS of thoughts on it (are you surprised?) and I can't even say for sure which I'd do if you handed me $60k that I "had" to use to go buy a new Jeep product. That said, I will point out that a JT (Gladiator) has almost a 3' longer wheelbase than my WJ... and overall length is actually MORE than 3' longer!!!!!
-TJ
