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I was going to start a new post but decided to start here. Tire pressures (not offroad) are totally misunderstood and go to any forum and finding any accurate information is an excercise in frustration. So I hope this simple reply will help a few of you determine your proper tire inflation based on your XJ's door inflation pressure lable if you decide to upgrade/downgradeto a different tire size which 95% of you will do. Before I start the numbers you'll find that what I'm listing are from an online calculator which just so happens to be correct. You can choose to call BS and do your own thing, but the facts are the facts.
Here we go.
My stock 96 tire size listed to the door was P215/70-15 with tire inflation listed as 33 PSI front and rear measured COLD.
Popular tire sizes and adjusted tire pressures for you XJ:
LT30X9.50. 31PSI
LT31X10.50. 26PSI
LT32X11.50. 25PSI
LT 33 AND LARGER ARE ALL 25PSI
Some run this 16 inch (approx 30 inch):
P235/75R16 tire pressure is 26PSI. This is a load range LT, not to be confused with a regular LT or LT metric with load range C,D E, etc.
Finally, LT Metric with load range C, D, and E:
The minimum tire pressure for all of these tires is 35 PSI even though the load they can carry is much higher than any XJ will need. Reason for this is based on the minimum inflation to prevent overheating will driving.
You state all your recommended tire pressures are under 35. Then you say "The minimum tire pressure for all of these tires is 35 PSI " you lost me. Can you clarify? Also does the weight you carry, bumpers, winch, lift cargo play into recommended pressure? I agree with you I have found recommendations to be all over the board.
Here is my setup. Its a Rustys 4.5 lift with Rustys 4-Link Longarm kit, fenders trimmed. I am currently running 33x12.50x15 tires that do not rub or hit at full flex with as much as 35 PSI. I would like to run 35x12.50x15 bead locks with 5-7PSI. for off road use only. Would trailer to riding parks and then use the 33s for on road use.
Would the 35s most likely clear fenders when running that low of PSI? In my mind I am thinking this should work but need some others vies, opinions and knowledge.
Thanks guys.
I'm lifting my stock 2001 XJ with a 231 and a Dana 35 rear axle. It will be a daily driver, hoping to travel 75mph safely and comfortably if possible (not too worried about mpg). Will be used off-road as well. I just took a screenshot of my shopping cart at rusty's offroad, and I was hoping that any of you could tell me if I'm missing anything important, or if I need to pick something else up somewhere else. My budget isn't limitless, but I can throw some cash around if I need to. I'm planning on 33s so gear ratio or driveshaft input would be nice as well. I'm trying to tighten everything up and improve the ride, but if the bushing upgrades are pointless let me know. I haven't asked anyone else this question, but will my stock brakes work well, or should I improve them? Any other advice would be appreciated as well. Thanks in advance
You state all your recommended tire pressures are under 35. Then you say "The minimum tire pressure for all of these tires is 35 PSI " you lost me. Can you clarify? Also does the weight you carry, bumpers, winch, lift cargo play into recommended pressure? I agree with you I have found recommendations to be all over the board.
Sorry I should have been more clear and I may rewrite it later to clarify with a table. Basically all LT metric tires, as an example 235/85r16 that have load ratings of C,D,E, etc have a minimum inflation pressure of 35PSI. In all cases that I looked at that pressure is more than adequate to handle any XJ with anything you add or carry or tow. Now that may not be case with 30X9.5, 31X10.5, Etc but in most cases it is. I'll take the time later to post a new thread with a table of all common XJ tire sizes, their load ratings, and maximum load per tire, etc. I think its worth explaining because many are taking a wild guess or using a chalk test, etc, but there are standards and formulas that clarify the correct tire pressure.
A sye and shaft from Adam’s is approximately $550. Needed for anything over 3” in my opinion.
From what I see that’s a short arm kit. No welding required.
Your stock brakes will work fine.
A good video of the installation of a long arm Kit on a 4-1/2" lift. Note, though a short arm kit may get you by, the improved geometry of a long arm installation is preferred for serious wheeling in my end of the country :
Hi, first time post on this forum.
I just purchased a really nice stock 92 XJ sport and would like to do a mild lift of 2" max, but I'd also like to level the rear with the front. Measuring from wheel center to the bottom edge of the fender flares I get 19.5" up front and 18" in the back. I read elsewhere on the forum here that 17.5" front and 17" rear is typical for stock, but I see no signs that the suspension has been modified from stock - except for the shocks. Is it typical for there to be some variability in stock ride height?
Currently my XJ is sitting on 235/75R15s with no rubbing, but I haven't tested at max compression. I'd like to fit either 30x9.5R15s or maybe 215/85R16s.
Cheers!
Hi, first time post on this forum.
I just purchased a really nice stock 92 XJ sport and would like to do a mild lift of 2" max, but I'd also like to level the rear with the front. Measuring from wheel center to the bottom edge of the fender flares I get 19.5" up front and 18" in the back. I read elsewhere on the forum here that 17.5" front and 17" rear is typical for stock, but I see no signs that the suspension has been modified from stock - except for the shocks. Is it typical for there to be some variability in stock ride height?
Currently my XJ is sitting on 235/75R15s with no rubbing, but I haven't tested at max compression. I'd like to fit either 30x9.5R15s or maybe 215/85R16s.
Cheers!
A 215/85/r15 (30.4") is too tall fro a 2" LIFT, HOWEVER, A 235/75/R16 OR THE 30X9.5/R15 YOU LIST WILL WORK WELL . To assess your existing lift:
Here is my setup. Its a Rustys 4.5 lift with Rustys 4-Link Longarm kit, fenders trimmed. I am currently running 33x12.50x15 tires that do not rub or hit at full flex with as much as 35 PSI. I would like to run 35x12.50x15 bead locks with 5-7PSI. for off road use only. Would trailer to riding parks and then use the 33s for on road use.
Would the 35s most likely clear fenders when running that low of PSI? In my mind I am thinking this should work but need some others vies, opinions and knowledge.
Thanks guys.
Want to run a Rustys 4.5” lift with 33” tires. What differentials and axels are you on? Those 15” rims? Super new to XJs, I have an 00’ with a 2” RC lift and 31”s that I want to make much more capable off road
I did a 2” spacer up front with 2” extended shackles in the back and 30.5 tires on 16” wheels.
the thing I’m running into now is the passenger front tire when I turn the wheel all the way to the right it rubs slightly on the lower control arm. It does not occur on the driver side and it doesn’t rub at all when turned left.
The Trac bar pulled your axle to the drivers side with the lift. Maybe enough to cause that. Did you drill a new hole on your axle side trac bar mount? Did you center the steering wheel after the lift?
09-21-2015, 02:17 PM
stucik trac bar
Long Arms = BETTER geometry
