I have a new-to-me 2016 JKU Rubicon Hard Rock, with Toyo Open Country MT 35x12.50x17 Load Range E. I was surprised to see they were inflated to 45psi, which seems like a lot. Also the salesman suggested air down should be around 18psi.
For reference, on my XJ, KM3 35x12.50x15 Load Range C, curb weight 4150, I ran 24psi on the street (chalk tested) and 12-14psi for rock & trail work. Aired down, the Load Range C KM3 had nice sidewall flex for sand/rock/slickrock. I don't have any experience (yet) with the stiffer Load Range E tires.
As soon as I can steal some chalk from a kid, I'll test it; but I am just looking for a starting point & anybody's suggestions.

Also, can I assume the Trail Rated fender badges are just adhesive mounted ? Looking to remove them.

 

Yes, 45psi is way high, but not uncommon to see tire shops and dealers pump em way up there not knowing any better. Those Toyos are a good tire for non-wintery climates but they will be stiffer due to that E load rating. 18 is awfully low. Regardless of chalk test, there's always going to be a tradeoff between comfort and economy. The caulk test will likely say lower, but most folks with 35s are running around 30psi I'd say. I have that same tire in a 37x13.5x17 and run mine around 26/27 cold.

 

Thanks. I'll start with 30psi, and then chalk test.
I should have been more clear, 18psi was recommended for trail, not street.

 

FYI.. We run the AT III same size on 17x9 wheels at 27 psi cold = chalked on a '13 JKU. good tread wear so far. we do not go lower than 18-20 off road = no beadlocks.

 

Thanks for the input.
Lowered all 5 from 45 to 30psi. I'll run that for a couple days, then drop to 27 & chalk test.

Tires are pretty new (spare hasn't been on the ground). Measuring tread depth I see a bit more tread wear in the centers, so I'm guessing the tire shop must have run them up to 45psi & the PO didn't have a clue. Don't understand how people mount big tires & don't even bother to use a pressure gauge. lol

 

Before I had beadlocks I would air down to 10psi and I only popped a bead once, that was a rare case too since I wasn’t paying attention to what I was doing.

 

Y, I'd agree that is takes way more to break a bead than most people think. I'd gone down to 10-12 on C rated tires that I would put up on walls and get very off camber with and only 1 time did I have a minor leak on the way home that I noticed due to TPMS. On E rated tires it's even harder. The only time I've been with someone that broke a bead on a trail was a numbskull situation of having to use his jeep as a winch point, and the situation only allowed for the jeep to be sideways and it was a really tough pull. Too much sideways pulling broke bead on his rear tire.