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RV-related and other recreational activities => 4-wheeling => Topic started by: UTTransplant on September 12, 2018, 04:40:12 PM

Title: Best replacement tires for Jeep Grand Cherokee
Post by: UTTransplant on September 12, 2018, 04:40:12 PM
Just discovered our 2018 GC Trailhawk has one tire with tread damage, non-repairable. Tire dealer said we had to replace all four tires, a very expensive proposition! 18,000 miles driven, maybe 3000 more miles towed. Can someone help me validate the need for replacement of all four? Also looking for recommendation of new tires if they are right. We generally donít off road much, but we like class 1 and 2 roads. The Jeep is totally stock. I am particularly interested in tires that can be aired down for a softer ride on washboards.
Title: Re: Best replacement tires for Jeep Grand Cherokee
Post by: SpencerPJ on September 12, 2018, 05:05:23 PM
Yikes, sounds fishy.  Can you tell us what brand tires they are?  21000 and need all replaced, sounds real fishy.  You did mention you run them low on air, I'm sure that is not good.  Maybe that played into it, maybe while towing you should run them closer to 35psi

I have a Yukon XL, but also had a kid with a Jeep, run Firestone Destination LE on both, and like them.  Tirerack.com is a great website for unbiased reviews.
Title: Re: Best replacement tires for Jeep Grand Cherokee
Post by: UTTransplant on September 12, 2018, 05:24:54 PM
Current tires are Goodyear Wranglers, OEM. We havenít run these low because they werenít rated for it, but I would like to be able to air down in the future if needed.
Title: Re: Best replacement tires for Jeep Grand Cherokee
Post by: Roy M on September 12, 2018, 05:29:31 PM
With full time 4wd I can see the need to replace all of them. One new tire will have a larger rolling diameter than the others which could cause driveline problems. As far as tires go it's a minefield out there, everybody has an opinion. Being in Iowa I assume you are dealing with a lot of rock and sand with little mud. I liked BFG All Terrain T/A for on and mild off road use but there are lots of choices. Talk to a reputable tire shop like Les Schwab or Big O.
Title: Re: Best replacement tires for Jeep Grand Cherokee
Post by: Gary RV_Wizard on September 12, 2018, 06:31:36 PM
I have limited experience offroad, but would never air-down except on trails and at very low speeds. Never drive at highway speeds without normal air pressure.  That said, you can run any normal highway tire soft (partially aired-down) for limited speeds & surface. We aren't talking 10 psi here, just down to its lowest pressure range per the tire model/size inflation chart. Really low pressure is for serious offroading only.  Is that what you meant about "washboards"?

You really need to learn more about what happened to require early replacement? What sort of tread damage and why?  And why all 4 tires?  I don't buy that the Select-Trak AWD system is so tire sensitive that it cannot tolerate some difference in tread wear.  The GC Trailhawk is still first & foremost a highway vehicle.
Title: Re: Best replacement tires for Jeep Grand Cherokee
Post by: UTTransplant on September 12, 2018, 08:40:40 PM
Thanks for the advice. We ended up going to Big O. We are in Estes Park, and they seemed the best alternative. We are having four new All-Terrain tires (Big O brand) put on tomorrow. They have a more aggressive tread than the OEM All-Weather tires, and are pretty close to the last two sets we out on the truck. The tire guy said we could replace just one tire if the wear difference was less than 30%, but we just went ahead and bought new ones. I am pretty peeved that the OEM tire had such a catestrophic failure. When we got it out to look ourselves, it was obvious the inner part of the tire was busted. It was bulging and leaking air. Sigh. Hopefully the new tires last longer! It is a pain to be on a trip and have this happen. Luckily we just took a car trip here, no motorhome.

As for airing down on washboard roads, I meant those few miles of dirt roads where the road plow digs groves, like a washboard. That is always the name we gave them growing up, so maybe it is a regionalism. When we had the truck where 60 pounds was normal driving, 80 pounds on rear for towing, we found airing down to 40 made a huge amount of difference in comfort. I am not talking about running on a highway at speed, just driving 10-15 mph on washboard sand/gravel/dirt roads for 5-20 miles. Like I said, we arenít big four wheelers, but we do like rough backroads and two tracks which is why I always had a Subaru before and now the GC.
Title: Re: Best replacement tires for Jeep Grand Cherokee
Post by: Ernie n Tara on September 13, 2018, 10:28:50 AM
You may be be a little overconservative. We probably take more exreme trails (usually 3-3.5 of 5) but  do have the stock rims. Off road I run 16 to 18 PSI with no problems and then back to 35 on the road. Speed is limited to less than 20 mph and probably 10 to 12 average.

I usually replace two tires at a time to make sure axle diameters are close but I doubt you would have a problem even at 30% difference in wear. That would not be all that unusual in normal service.

Ernie
Title: Re: Best replacement tires for Jeep Grand Cherokee
Post by: Gary RV_Wizard on September 13, 2018, 11:10:57 AM
The lower limit on psi is basically whatever it takes to keep the tire on the wheel.   I see no problem in dropping a 60 psi tire to 40, but dropping a 30 psi tire to 10 is probably risky.  The 16-18 that Ernie does should not be a problem at 10-15 mph.  What would be the Normal highway inflation on the new tires? Something like 35?

In your situation, I would probably experiment by dropping 8-10 psi and driving a few miles on that washboard.  If still too rough, try another 5 psi. It's been years since I owned a 4wd vehicle, but mine actually ran smoother on those washboard roads in 4wd - less skittering around. 
Title: Re: Best replacement tires for Jeep Grand Cherokee
Post by: Old_Crow on September 14, 2018, 09:22:30 AM
In regards to normal pressure, Gary, my '03 Wrangler TJ running stock size 30x9.50/15's calls for 29 psi on the door placard. 
That's the same size I used to run on my old YJ(several sizes oversize for that application).  I experimented with different pressures to find one that wouldn't run the center out of the tread and lo and behold...ended up with 29 psi.
I don't have on-board air, or friends to off road with(most of the time)so I've never really experimented with airing down.  Maybe at the Q this winter.
Title: Re: Best replacement tires for Jeep Grand Cherokee
Post by: John Canfield on October 02, 2018, 08:38:59 AM
All of the tires commonly used for off-road can be aired down, the limitation is actually the tire rim (or wheel if you like). The stock Jeep Moab wheels are quite excellent and will hold a bead down to at least 12 psi. I have Trailready HD beadlock wheels and run my Nitto Grapplers at 6 to 8 psi on the trail and about 20 to 25 on the highway.

The way to determine proper inflation is the 'chalk test' rub a bunch of chalk across the tread, roll the vehicle forward and check the contact area between the tire and ground. Adjust the air pressure until the full width of the tire in contact with the ground.
Title: Re: Best replacement tires for Jeep Grand Cherokee
Post by: Ro and Joe on December 27, 2018, 04:39:11 PM
Where I grew up, we would reduce pressures to around 12psi on soft sand.  Really increases surface area and much less stress on drive train.
Title: Re: Best replacement tires for Jeep Grand Cherokee
Post by: Larry N. on December 27, 2018, 05:41:00 PM
Current tires are Goodyear Wranglers, OEM. We havenít run these low because they werenít rated for it, but I would like to be able to air down in the future if needed.
I'm still running the OEM tires on my Wrangler -- they're Bridgestone Dueler A/T -- and I've run them as low as about 12 psi on the trail, once, but I think 16-18 is a better setting, much like Ernie said. At 12 psi there is too much sidewall on the ground. And yes, it helps the washboard ride tremendously.