i would run them in the 29psi neighborhood. 33x12.50's are normally 26-28 depending on how it's loaded. You don't have quite as much surface area with 10.50's.
My best suggestion would be to do the chalk test on your tires. Doesn't take much time at all. If you're unfamiliar with it just do a google search or forum search for Tire Chalk Test. I did this with the 265/70/17 on my tj and ended up with 27 in the rears and 28/29 in the fronts.
The problem with a chalk test is that it can often lead to under inflation which is way worse than being a little over inflated. I suggest you just go by what is already known by the real world experience of those who have been doing this a really long time.
I can tell you that 27psi in the 31.5x10.5 tires that you have is under inflated for the weight of your Jeep no matter what you think the chalk test says.
WD not to derail this thread and please don't take this as being confrontational. Even while running 30psi in my rears "Grabber AT2 Tires" I was getting abnormal wear in the centers of my tires.
As a serious question, what would you suggest I run seeing that the chalk test and ocd like checking of my tires, has seemed to make this issue stop? I am not seeing any adverse wear on the shoulders of my tires or even sidewall wear or rolling while cornering.
Keep in mind the Jeep in question is driven on average 700 miles per week at almost all highway speeds and 20 miles a day of this is twisting back roads getting to civilization.
i run 26 in 32 inch tires and they do not get hot or have any issues if your wearing the center out you need to drop the pressure.this is cold tire pressure.there are a lot of folks who run 24 and some less and never had issues common sense goes a long way here.and i also run 75 down the freeway.
If I am understanding correctly, the median pressure (between under inflation, which can increase heat and cause outside tread wear, and over inflation, which reduces heat but can cause center-tire wear) is the ideal for a person's vehicle
You say don't use the chaulk test but don't give a good way to figure out how.
Personally done right I recommend the chaulk test. But do it right. Start with an over inflated tire. Drive it several miles so it heats up. Then do the chaulk. Take air out until you get the contact patch you like. I would not go lower than 26 psi tho. My reasoning is 26 is the lowest you will find on any stock vehicle.
The larger the tire (more contact area with the same load rating), the lower the air pressure should be for a given weight. I run my 35x12.50's at 25psi.
24-26 is typically recommended for 35x12.50 load range "C" tires carrying the weight of a TJ
I keep my 10.5 32's at 32psi on 16" rims for no reason whatsoever. It's right in the middle of what these people suggest and feels right so I go with it.
Hopefully they'll come to a consensus before I get my next TJ in a few years.
I just got new wheels and tires. 20" wheels with 35x12.5 BFGoodrich KO2. The tire place filled the tires to 70psi. That seems extremely high to me. Reading this thread leads me to believe it should around 25? Any help would be great as I don't want to were out these new tires
Should be a sticker somewhere in the door jamb that tells you what the OEM suggests tire pressure should be for a stock Jeep. Then do a chalk test for your's
There is probably a weight/pressure chart for the tires somewhere. Somewhere, enshrined in a little folder is a study in black and white of YOUR TIRES and their proper inflation based on load. ... and what a load it is.
my 31x10.5x15 run best on road @ 30#, less feels spongy. tires wear flat and true, all our rigs are diff , use this as starting point find ur sweet spot for ride quality, keep eye on tire wear
I have been wondering about this as well since I have been using 35# in same on-road for mileage & handling. I do so in all my cars since I prefer response to a bit stiffer ride.
Going to bump down to 30 for a while (& do chalk /temp test)
This thread makes me think my tires are way over-inflated (I'm new to Jeep ownership, came in from a Camaro)! The info inside the door says 35 psi cold, so that's what I have them at. What changes in the ride, etc. will I see if I go down to 30 psi?
Yes i did. I'm going to have those greenish spokes painted to match the jeeps color. This is the only pict i have of it right now.
As for the 20" wheels that still gives me 7.5" of side wall on the tire:[/QUOTE]
That's actually a pretty sharp looking color scheme IMO.....but I'd ditch the angry grill.
Love the black grill though.
Oh almost forgot to mention, 33's running 26psi with top and doors off and 28psi loaded.
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