OnTheHunt: Excellent article. Thanks for posting.

For everyone: If you are looking for a 10-ply highway tire in Load Range E, allow me to suggest the BFG Commercial T/A tires. I am currently using these in a 215/85-R16 size, at 80psi. They are wearing perfectly square, as that is how they are sitting on the pavement. Even at 40psi, they did not have a load bubble (which is NOT an indication of proper or improper inflation, it only indicates a soft sidewall) but had much more noticeable heat loading after a drive. 60psi would be the pressure I would suggest for anyone using these who wanted a softer ride without compromising the tire's life. I don't mind a firm ride, its really not that much different than at the 40psi, but the car is a LOT less sloppy than with the stock P-tires. Besides - This is a Jeep. Its designed for function, not for a Lincoln Town Car ride. You can't pull 7k and go offroad in a Town Car.

RE:



Okay.. this is good info.

However...

This does not address the contact patch area, safe stopping distance issue that others have mentioned.

Darby, sorry... what is Auto-X... is this racing?. I suppose braking is very importantin racing. You gave a qualitative comparission.... but I was looking for some cold/ hard facts. Has there been a test of LT tires at different pressures during emergency breaking?

It seems like the danger of tire failure due to underinfaltion and high temperatures might outweigh the stopping distance increase.

Okay.... I am taking the tires up to 50 psi now, given the NITTO info.

I really appreciate the great discusssions on this forum!

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06 CRD LTD - Suncoast TC- Shift Kit - Spicer UJ - FRKNLIFT - F37 - Magnaflow - 22.0 City - 24@65MPH - Fumoto F-102 - AUX T Cooler - Tank Lift Pump

you can't pull 7,000 pounds in a KJ either...

Actually, Panther-platform cars have the same towing capacities as a KJ. 5k with towing package, 3500 without (going from the top of my head)

fastrob, BFG Long Trails are what I'd get in your position...in that size...in a 4 ply. You don't need 10 ply tires on a street driven KJ. If you're going off road...go with something a little more off roady:)

Found some more tire manufacturer info that confirms that the correct MINIMUM safe pressure for 245 75 16 E on a Liberty is 40 psi for 1800 lbs load per tire. Interestingly, at 60 psi the load capacity is 2480 per tire... only 37% more. This is from the "TRA Light Truck Inflation Table"

See

http://marktg.toyotires.com/file/loadinflationtable.pdf page 9 for the LT pressure vs load table.

Note the take home message in the above document is the same as in the Nitto posted previously;

WARNING! Please note that size for size, LT-metric tires require higher air pressures
to carry equivalent loads of P-Metric tires and that any failure to adjust air pressure to
achieve the vehicle’s load requirements will result in tire fatigue and eventual tire failure
due to excessive heat buildup. Due to the higher PSI requirements of LT-Metric tires they
may not be suitable for replacing O.E. P-Metric tires because of the ride harshness that
results from higher PSI.

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06 CRD LTD - Suncoast TC- Shift Kit - Spicer UJ - FRKNLIFT - F37 - Magnaflow - 22.0 City - 24@65MPH - Fumoto F-102 - AUX T Cooler - Tank Lift Pump

DING DING DING!!! We have a winner!

I have had to panic stop a couple times since I've gotten my BFG 10 ply tires, and I haven't noticed any increased stopping distance on the pavement. I haven't hit anything either, or slid, so I'd say the tires are working just fine. Now if Bambi would stop testing me and trying to cause me a heart attack... That would be nice. Gotta get some of those deer whistles.

So, my Trxus are load range C. What psi should I be running? I run 36 psi right now.

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My Jeep Build ----> Big Black

Seriously...35 psi is not going to cause a tire failure due to underinflation on a 6, 8, or 10p tire on a stock KJ. Geordi, I remember your story about a blowout on your RV. the 12 or 14p tire on your RV (120 psi max) blew out when it was at 70 psi is because of underinflation. Your KJ didn't come with 10 plies so there is ABSOLUTELY NO REASON to run them at 80. the reason your RV's tire blew out when it was only inflated to 70 psi is because the load range of the tires are REQUIRED for your RV's weight, not because you weren't close to the max.

an LRC (6 ply) will also be fine at 35-40, mike.

How's your kidney's?

I run 43 psi in my load range "D" tires,22psi from the max of 65psi,and they ride very rough compared to 35psi but the best wear at 43psi,and I weigh at least a 1000lbs more then you.I never ran that much psi when I did run "E" rated tires,just to much air and can do just as much harm as being under inflated,your tires are transmitting to much road shock to your suspension and will wear out components faster running at that psi..No way your wearing correct at 80psi in a KJ,even a CRD,not heavy enough.

Oh and that "load bubble" is not a indication of a soft sidewall,it's a radial tire thing and is normal if you are at proper tire psi.

You'll be fine at that psi,add anymore weight and you may need to bump up 2-3 psi for correct wear.I run 43psi in mine but I'm at 5500lbs without me in my KJ.

Thanks TBirdJunkie and TJKJ. I thought so, but all this info going back and forth had me wondering. Thanks fellas.

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My Jeep Build ----> Big Black

I don't know what a Panther platform is, but when the towing specs in the book are the same for a gutless V6 as they are for the high-torque diesel, something is decidedly fishy. IIRC, the European KJs (Which are THE SAME CRD as here) are rated for 7k, and with my nice strong 4-cylinder baby hooked up right here, and its load range E shoes... I didn't even need to try putting it in 4wd to pull that load.

I pulled a FULLY FUELED MQ Power 70kw genset on a tandem-axle trailer. Ran it across the scales just for giggles, and I was pulling down 18mpg while a little 4-cylinder diesel was moving just over 11k lbs of gcwr, 6840 of the generator. Not that much tongue weight for that size, since its a purpose-built unit. 400 lbs IIRC. 18mpg. At 65mph, up and down some mild hills. Yea, acceleration wasn't as quick and easy as when unhooked, but stopping was a cinch b/c the genset was wearing it's own hydraulic brakes. Stopping distances felt about the same to me, maybe a *little* longer.



As for anyone needing or not needing 10 ply highway tires... I think every trucker in the USA might disagree. And for personal non-heavy hauler vehicles? Isn't that more of a personal choice? I chose vehicle mileage and tire longevity. Using any product to it's maximum capabilities is inefficient - Why buy "Heavy Duty" tools when Black and Decker (or Chicago Tools for that matter) would do? Probably b/c you want to have the tool longer than just this one job.

Yea, my tires might not normally be carrying 3000lbs per wheel. But because they aren't, they aren't heat loading or prematurely wearing. I like that. Cool tires are safe tires. The only place where I have experienced any extended stopping distances? In the mud off-road. These pizza cutters dig right in, and yea, they do slide around and plow a bit. But hey, thats the fun of mudding. And they haven't gotten me stuck at all - quite the opposite. I've pulled out a fully loaded 10k lb box truck that was stuck rim-deep in the mud, and pulled it (with it helping some once it was out of the hole) about 2 blocks to get back to the paved road... And I've pulled out a 2wd Explorer that really shouldn't have been where it was... SIDEWAYS. Yep, I pulled it sideways out of that mud, and I was rim-deep in it myself at that point. And the KJ didn't have any problems getting back to the pavement with my 10 ply highway shoes.

I like them just fine, and will be putting 10 ply tires on all my SUV vehicles from now on. (2 Mercury hybrids and a Jeep Grand Cherokee)

Oh, and one more thing in their favor: Made in the USA.

My kidneys are just fine, thanks. I've said this before, and I'll say it again here: Anyone is welcome to come and test-drive my KJ anytime they would like to see exactly how these tires compare to whatever everyone else is using. I'm in Savannah, Ga right now, and will be in New Hampshire all summer starting in about 4 weeks. Weight-wise, my KJ is basically stock, and the ride is just fine for me. Yea, potholes don't feel rear great, but I'm not getting bounced out of my seat at all.

Oh, and Thunderbird - About the RV tire blowout: I don't believe I ever said they were at 70psi, but the real reason they let go had less to do with pressure, and much more to do with the fact that the tires were more than 10 years old, AND it was in Texas in the middle of the hottest August in many years. That will spell doom for MANY tires. Also, I don't believe these were 12 or 14 ply, but I will check on that tomorrow. I still have one of those, as a "spare" that will be an emergency-use-only until I can actually get rid of it eventually. It will be replaced with a GoodYear AllSteel RV tire like what is on all 6 rims currently.

I must admit that on my previous set of tires (load E) I went with 70 psi and the wear was perfectly normal, and the ride was fine. Maybe my Frankenlift springs and shocks were helping out with this effect? I had many passengers including a very picky wife, and a dainty Mom say nothing about a harsh ride. I guess I have been avoiding the "bummpy ride" qualitative part of the "tire pressure" issue, because it boils down to preference.


At 50 psi in my new R/Ts, the ride is plenty cushy. Ya, I have 22% more load capacity by pressure than required. Ya, I can stick a business card 1/4" in either side of the tire footprint, so I have lost some contact area. But the sidewalls will be running cooler, and the mileage will be better. This is where you have to pick your own preferences.

I think it is important that folks know that, in the change from P to LT, the required pressure will be greater, and in some case, a lot greater. For load range E 245 75 16 the tire pressure needs to be 21% higher, even if the ride is percieved to be rougher.

It is also pretty obvious now that running 60 psi in a load E tire is not as nutty as some might think!

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06 CRD LTD - Suncoast TC- Shift Kit - Spicer UJ - FRKNLIFT - F37 - Magnaflow - 22.0 City - 24@65MPH - Fumoto F-102 - AUX T Cooler - Tank Lift Pump

Thanks for the input Bill, its nice to know that the LRE trail has been driven before by others, and to get some confirmation on the performance and ride.

Some just won't believe me that modern tires are designed to ride square, and that the difference between low pressure and high pressure is a front-to-back contact patch extension. That, and narrower tires are much less likely to "round out" in the center of the tread simply b/c they don't have the surface area to do so as much as a wide tire.

Anyway, its the educational value that is provided here. Everyone must make their own choices for their ride, hopefully they are making a more informed one now.

educational choices......but I wonder where they get the education.....must be from Walmart brand cereal boxes, I have never heard so many things about running high air pressure that is out and out bad advice in my life!

Good luck in running 55/60/80 lb!

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MUDD'S MOTORSPORT'S We do IFS lift installs ,
03 OVERLAND EDITION /Kilby-Skidrow-Mopar-4XGuard skids/ 2.5 inch TOTAL CONTROL JBA coilovers -JBA Arms/MOABS-31 FALKEN WILDPEAK AT3W / 4.10's etc, 04 Kilimanjaro Edition loaded, plus 05 KJ limited

Here we go again....Engaging warp drive...

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LOST # 633
'05 KJ 3.7L/6spd/241 245/75/16 MT's
'88 MJ 4.0L/AW4/231 SWB HPD30 & trac-loc D44 w/3.73's
A dirty Jeep is a happy Jeep

educational choices......but I wonder where they get the education.....must be from Walmart brand cereal boxes, I have never heard so many things about running high air pressure that is out and out bad advice in my life!

Good luck in running 55/60/80 lb! [/quote]

Wow... That was very helpful to the masses. You haven't ever heard so many things that you don't have any personal experience with, but you feel the need to share hearsay anyway. Thank you for the profound assistance and useful information other than the "out and out bad advice" comment.

I'm posting about my personal experiences. Not anyone elses. If a tire fails, I want to examine why it failed, to prevent it from happening again. Some of the personal experiences I have, may be different from other people because I own a variety of vehicle sizes. I talk to others, but I temper that with my own tests.

My own tests have shown that while the ride might be a little harder, tires run cooler, last longer, and provide better mileage and equivalent stopping distance. The RV tires that blew, I had been running them at 110psi before I lost the first one. I lowered the pressure because I believed that a shock to the tire had caused the blowout, and was trying to soften them just a bit. It didn't help, I traded firmness for flexing, and the heat probably killed the second one. In actuality, extreme age plus the insane heat was the most likely factor in both failures, and they blew across the tread from wall to wall. Not a peel-off.

One year a long time ago, 2 different cars in my family that got a total of 8 tires from the same place at the same time... Had bubbles develop on 6 of them. Obviously a manufacturer defect. I have gone through 2 full sets of Michelin tires on one of my cars, not even coming half-way to the mileage ratings of the tires. Treadwear 680 rated, 80k mile, lucky to see 35k before the markers. Not worn unevenly, just melting away. Yet some Falken 440 rated 40k tires got every mile on the drive wheels, and more than twice that on the drag wheels. ALL were run at full sidewall pressure, and wore evenly.

As a personal testament to the inaccuracy of the old idea that full inflation will make a tire balloon out in the center, those Falkens were 195/65/15 on a 2800 lb Jetta... And the shoulders of all four tires wore faster than the centers at 55 psi. Tire shop monkeys wanted to charge me $75 for an alignment, while I was trying to tell them that an alignment problem could not cause this... As the tires were never rotated for their entire lifespan. Never. Wear of both the edges of the tire are usually an indication of UNDERinflation... Except when the car is driven like its on an autocross all the time. That was how I drove it, so I KNOW what caused the strange wear. It was not a mechanical issue - it was user caused.

Currently, I am using the tires I chose after careful consideration of sizes, cost, wear ratings, and my own experiences with the large vehicle tires that these BFGs are based on. I am running them at a pressure choice based on my experiences. Is it any different than any other non-OEM experiment that we all do? Doubtful.

See how personal experiences are more informative than just repeating what someone's friend's brother's tire guy once told them while recalling his life?
Please try to do the same, rather than just a blanket "Oh thats such bad advice but I won't ever back up my claims" comment.

those look like an AT in the center and an MT on the outer lugs. Interesting design.

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-Jon-
02 Jeep Liberty - LOST Trail Tested Edition - sold
09 VW Tiguan 4motion - current

Yep, but they handle the mud quite well, and are quiet on the road.

Wow, geordi, I bet your KJ really stops nicely with 7,000 pounds behind it...

American towing capacity takes into account the brakes. My KJ CAN pull 10,000 pounds if I WANT it to. Can it stop? HELL no.

It pains me to see that you're being a danger to not only yourself, but others...and due to your "Experiances", it appears you've dodged a LOT of bullets to prevent removing yourself from the gene pool. Nice job, Neo, you must be The One.