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Tire pressure makes huge difference in ride quality

VGxHC

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When the off-road shop installed the new wheels and tires, they informed me the tires were aired to 40 psi. I knew this seemed a little high but a day or so later they were down to about 37 each. For 3 weeks of feeling every pebble and paint line on the road, I finally decreased the tire pressures to 32. I am amazed by how much difference in ride the 5 psi makes.
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ECHO

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Ohh yeah it’s a huge difference, normally chalk test my tire and have found 28 -30 is a good psi for MUd Tires
 

SpringsJL

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I can’t leave the dealership without them airing my 35s to 38psi it rides like it has no suspension. Have to air them down every time.
 

alrola

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I have a JLUR with 2” lift and 35 “ KO2 and have found that the chalk test is good at 30-32 psi. More importantly I found that when they warm up to above 34 I can tell just by the ride without looking at TPMS
So, in Florida in winter I had it at 32 which stayed at 32-33. Now getting warmer and days at 85 I aired down to 31 which will come up to the warm seeet spot if 33.
Hope that makes sense.
My PREVIOUS dealer (I have an awesome one now in TAMPA) was airing it to 44psi and both mechanic and foreman supposedly were jeep people.
 

ChattVol

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When the off-road shop installed the new wheels and tires, they informed me the tires were aired to 40 psi. I knew this seemed a little high but a day or so later they were down to about 37 each. For 3 weeks of feeling every pebble and paint line on the road, I finally decreased the tire pressures to 32. I am amazed by how much difference in ride the 5 psi makes.
Interesting topic...especially considering our jl's are lightweight vehicles compared to most other trucks and suv's. 315/70/17 ko2 load range c on a 8.5" wide wheel chalk tested well at 30psi. Most load range d chalk test well around 23-25 psi and load range e even lower. Our jeeps only weigh 4500 lbs unloaded and jeep engineers chose a load tange c for the rubi. Ford raptor weighs 6600 lbs unloaded and was also designed with ko2's load range c. Point being...load range c is more than adequate for the jl's weight. If you want to have good sidewall flex and a smoother ride, load range d and e is overkill for most jeeps unless you're towing heavy loads. I wish there were more load range c 35 and 37" tire options targeted for the jl.
 

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drdriller

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Interesting topic...especially considering our jl's are lightweight vehicles compared to most other trucks and suv's. 315/70/17 ko2 load range c on a 8.5" wide wheel chalk tested well at 30psi. Most load range d chalk test well around 23-25 psi and load range e even lower. Our jeeps only weigh 4500 lbs unloaded and jeep engineers chose a load tange c for the rubi. Ford raptor weighs 6600 lbs unloaded and was also designed with ko2's load range c. Point being...load range c is more than adequate for the jl's weight. If you want to have good sidewall flex and a smoother ride, load range d and e is overkill for most jeeps unless you're towing heavy loads. I wish there were more load range c 35 and 37" tire options targeted for the jl.
Right on!
 

roaniecowpony

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I pushed my fuses in and my ride was smoother.
 

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It seems like a topic that is commonly overlooked. I'd be willing to bet the vast majority of jl owners running 35s and 37s load range d and e are running too much air on road resulting in uneven tire wear and a stiffer ride.
So I got my 35” D rated tires mounted and balanced and when I put them on discovered they were all inflated to mid-40’s. I brought them down to 33. They are still harsher than I’d like compared to the comfy C rated 33’s. Do you think lowering the pressure more would help?

Also for those that don’t have a programmer, do you just ignore the TPMS warning?
 

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melendez69

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I have a JLUR with 2” lift and 35 “ KO2 and have found that the chalk test is good at 30-32 psi. More importantly I found that when they warm up to above 34 I can tell just by the ride without looking at TPMS
So, in Florida in winter I had it at 32 which stayed at 32-33. Now getting warmer and days at 85 I aired down to 31 which will come up to the warm seeet spot if 33.
Hope that makes sense.
My PREVIOUS dealer (I have an awesome one now in TAMPA) was airing it to 44psi and both mechanic and foreman supposedly were jeep people.
But did your previous dealer move your seat around? ;)

I'm kidding... it's a little forum humor. I had my dealer replace my wheels about a month ago & instructed them to keep the pressure at 35. What did they do? A ridiculous 42 psi.
 

JIMBOX

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The "CHALK TEST" is a waste of time and NON-ENGINEERED TRIVIA-

Since 2006, the JK/JL 2dr/4drs have gotten the best ride/wear between 28 psi and 32 psi--a waste of time screwing withit--just leave them at 30 psi !

I don't worry about the TPMS SYSTEM--I run without wheel xmitters-

W.E.

JIMBO
 

Robmypro

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So 35 PSI is the desired pressure for a Rubicon with 33" tires?
 

IronScott

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I have 295/70/17 KM3 tires. I had them at 35/36 and they felt pretty good but after installing a lift (RC 2.5 full) I noticed my ride was much more harsh. Started airing down a bit and trying new levels. At 31 right now and they feel so much better. I might go down a couple more but it feels pretty close to stock suspension now. Amazing how much difference it can make, especially on stiffer sidewalls and/or heavier tires.
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