Recommended KO2 Tire Pressure

kah.mun.rah

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Rim width plays a major factor in contact area
Exactly. So does vehicle weight, driving altitude, air temperature, etc. Just like picking the right gear ratio, there are so many factors to consider that there is NOT a one size fits all when it comes to PSI for a specific tire size no matter how much @CarbonSteel wants it to be his way or the highway.

 

Vinman

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FWIW,
I ran 15x8” rims with 12.50 wide KO or KO2 tires on all my previous TJ’s and have never had full contact tread unless tire pressure was ridiculously low, like sub 20 psi.
I always ran around 26 psi on those Jeeps.
 

JEEP4U

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Not a fan of the K02...........they are horrible in mud !!!

But, I run my 40" Maxxis Razr AT at 34 cold.
 

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Exactly. So does vehicle weight, driving altitude, air temperature, etc. Just like picking the right gear ratio, there are so many factors to consider that there is NOT a one size fits all when it comes to PSI for a specific tire size no matter how much @CarbonSteel wants it to be his way or the highway.
LOL - not at all--it is more about confirming facts and data. Given that most people who have posted here that 37" K02 tires do not have full contact at 30PSI, unless you are running really wide wheels, having it at 35PSI seems less than probable.

EDIT - My JLUR weighs 5970 and therefore would be more likely to have full contact patch versus lighter Jeeps and it does not even at 30PSI on 17x8.5" wheels and they are Load Range C which means software sidewalls so there is that...
 
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TheAmericanB

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My ‘23 JLURXR came from the factory last week with 45 psi in all the 35s! 🤯
 


No IFS

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Every combination is different. Do the chalk or water test to determine your correct pressure. Tire pressures are listed as guides for legal reasons. The tires fit many different vehicles.
 

kah.mun.rah

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Every combination is different. Do the chalk or water test to determine your correct pressure. Tire pressures are listed as guides for legal reasons. The tires fit many different vehicles.
⬆ this
 

gato

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Not just for Jeeps, but the tire pressures in the door sticker by the manufacturer these days are set up mostly for fuel economy reasons. They are typically set up as the maximum pressure they can get away with, without a massive impact on ride and handling qualities.

For most vehicles these days from Jeeps to sports cars, running a pressure lower than the door sticker provides much better ride and handling.

For very high profile tires, like on the Jeep, pothole performance is not much of an issue, so experiment and set a tire pressure that gives you the best ride, while not rolling too much on corners to affect handling.

For KO2s I've found that on a very heavy 4-door, 28-30 works great for 37R17 and 30 works great for 33R17.
 


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Can anyone post a pic of what the factory sticker is on a Rubicon with 285/70/17 KO2's? Everyone is reporting 37 and that is what I am tending to go with.
 

kah.mun.rah

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Can anyone post a pic of what the factory sticker is on a Rubicon with 285/70/17 KO2's? Everyone is reporting 37 and that is what I am tending to go with.
Here you go but as others have mentioned, best to run a chalk or other test to see what is best for your setup.

1664388391535.png
 

CarbonSteel

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Out of curiosity, has anyone determined what PSI (generally speaking) it takes for full tread contact on 37" K02's?

I have to deflate into the mid-20PSI range for that with LRC 37" K02's on 17x8.5" wheels. Others?
 

kah.mun.rah

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Out of curiosity, has anyone determined what PSI (generally speaking) it takes for full tread contact on 37" K02's?

I have to deflate into the mid-20PSI range for that. Others?
On my 2021 JLUR with 37x12.5R17 BFG KO2, 18K miles of wear on the tread, 17x8.5 TeraFlex Nomad wheels, and one occupant weighing 205 lbs, the results of a chalk test and an ARB Digital tire pressure gauge at sea elevation, 75 degrees outside with a slight wind from the south-west, my best wear pattern came in at an average of 35psi.

That said, there is not a one size fits all and rather than relying on the results of other peoples' experiments I recommend that readers do their own chalk (or other) test to see what works best for their setup and environment. One more note, a regular rotation of your tires is just as important as PSI if you want to extend the life of your tire.

All of this said, if you are like me and the trail damage and/or desire to upgrade your tire size come into play before your tread is gone anyway, just run the PSI that feels best for your driving comfort.
 

CarbonSteel

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On my 2021 JLUR with 37x12.5R17 BFG KO2, 18K miles of wear on the tread, 17x8.5 TeraFlex Nomad wheels, and one occupant weighing 205 lbs, the results of a chalk test and an ARB Digital tire pressure gauge at sea elevation, 75 degrees outside with a slight wind from the south-west, my best wear pattern came in at an average of 35psi.

That said, there is not a one size fits all and rather than relying on the results of other peoples' experiments I recommend that you do your own chalk (or other) test to see what works best for your setup and environment.
Right--I have and posted those results above so thanks for your input.

Curious as to what PSI others have had to go to gain full tread contact.

 

ATO4x4
 
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