28 / 25 PSI - Are you kidding me ?

[toddarama]

I run 28 cold in my JTR with 37" Mickey/Thompson BB A/Ts - I've tried higher pressures but then handling gets a little squirrely on the expressways

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[Osteodoc08]

Stock Mojave and I run 32psi cold year round

 

[Dougstdig]

Kinda doing some backward analysis here. Stock tires come load range C. Load range D or 8 ply tires have a 50 psi max. You stated your tires have a max PSI of 65? That’s a lot of tire for a gladiator. I also didn’t see where you mention the wheel size. Many 18” wheels running 35-37” tires with a max pressure of 65psi are load range E or a 10 ply tire…meant for 3/4 or 1-ton single rear wheel trucks.

 

[Jteakus]

I run 33 psi in 37 KO's C rated

 

[SargeDiesel]

You're welcome. I am the king of worry, so I usually double check and ask a lot of questions, lol

You see what Im doing... ha ha

 

[SargeDiesel]

You're overthinking it

Drive where it feels best

I stay around 35 cold

Appreciate your input, but I'm not sure I would 100% agree about over thinking it. Your suggestion is how I landed at my current PSI... according to the treadwear, its too high. That said, I do understand where you are coming from though. ?

 

[SargeDiesel]

However, if towing or carrying a heavy load, especially if routinely traveling at highway speeds, research how much pressure to add to avoid overheating the tire. Get used to how hot the tires usually are and check for increased heat during those long hauls. If they're getting toasty, add more air.

Great information, thanks. Is there a proven method for this ? Or do you just go by feel or in some cases, smell.. lol

 

[SargeDiesel]

Try This Method.. I run at 27psi on the Mojave and 28 on the JKU per the test results.

Thanks, I've watched this video and several others... as I mentioned in my opening post, I still need to do the chalk test. But I needed a little more knowledge about proper PSI inorder to trust my findings. Thanks for the input !

 

[TARHEELKIDD]

If all else fails, go to your tire manufacuter's site. They usually hace a contact method/email. Send them them exact tire and the make, model and year of your Jeep. They will tell you exaclty where the PSI needs to be. On my 2014 Silverado, the door jam ricommended 70 PSI for my 325 x 60 R20, KO2 A/T. It rode like it was on ballons. The MFG informed me it should be between 50 to 53 PSI max. It made a huge difference. When I traded it in, I had approximately 10,000 miles of thread left and alredy had over 53,000 miles on them.

 

[WILDHOBO]

Need help , advice please.

Typically I have only ever dealt with car tires and have basically stayed with the recommended tire size/PSI listed on the door jam.

New to the big tire game, I have just stuck to what I know (atleast though I knew).

I have 37" all terrain tires
with a max load/ PSI rating of 3525 @ 65.
I have tried running them as low as 32 PSI and as high as 37. I found the low, to be squishy and the high to be squirly... so I settled around 34/35.

I'm getting close to my first tire rotation, so I started paying a little more attention. It seems my pressure might be a little high, so I started researching.

I haven't done a chalk test(yet)
I haven't weighed my actual vehicle (yet, looking fo a reputable scale clost by)
So I grabbed the weights for a 2022 JTRD from the web and estimated for the larger wheels/tires/lift and rock sliders and came up with the following numbers:
*These numbers are not verified in anyway, just best guessed according to what I could find on the internet. Please correct if grossly incorrect *

Curb weight - 5550
FAW - 2925
RAW - 2625

Using a PSI calculator, it gave me the following calculations:

Front PSI - 28
Rear PSI - 25

Those with first hand experience or tire expertise (self appointed is ok... ha ha)

Does this sound right ?

I know I need atleast to do a chalk test, but want to be more accurate, so weighing at a scale is preferred.

Should the 28/25 put me in the ball park or should I continue to run 34/35 all around until I can verify my actual vehicle weight ?

What PSI are you guys running for your 37's ?

Thanks for your help/input.

Call the tire manufacturer. I called Mickey when I thought I was running high as well. They asked detailed questions about the Jeep, including original tires and door label. They recommended 27psi cold for my 37’s. They were spot on. Its rides perfectly and wears evenly.

 

[SargeDiesel]

I run 38 psi may till sept. 32 the rest of the year. Hwy tire temps drive the psi need up in fl summers

Here in Alabama, we get some hot summers as well... typically hotter than my Cocoa Beach house in Fl. But there is always a breeze on the ocean.... it does get very hot in Orlando and inland. How do you determine the additional PSI vs. Higher Temperature ?

 

[WILDHOBO]

Here in Alabama, we get some hot summers as well... typically hotter than my Cocoa Beach house in Fl. But there is always a breeze on the ocean.... it does get very hot in Orlando and inland. How do you determine the additional PSI vs. Higher Temperature ?

I adjust throughout the year as necessary.

 

[SargeDiesel]

Kinda doing some backward analysis here. Stock tires come load range C. Load range D or 8 ply tires have a 50 psi max. You stated your tires have a max PSI of 65? That’s a lot of tire for a gladiator. I also didn’t see where you mention the wheel size. Many 18” wheels running 35-37” tires with a max pressure of 65psi are load range E or a 10 ply tire…meant for 3/4 or 1-ton single rear wheel trucks.

37x12.5x17 you are correct, it is a E/10-ply.... but
A heavier tire means that there is more rubber, which translates into deeper lugs that provide better traction and thicker, stronger sidewalls. There is still value to running a Load Range E tire on a lightweight off-road vehicle. While the carcass will not be as flexible as an equivalent tire in a lower load range, the air pressure can be lowered to account for this. The reason the carcass is less flexible is because of heavier construction that fends off punctures off-road.
Getting the proper PSI, is a little more tricky with the range E tire, heat is the killer as @ScottBeach mentioned.

I got this info from a great Motortrend article, you can read the whole article here:
https://www.motortrend.com/how-to/1611-tire-tips-101-load-range-vs-weight-rating-and-more/

 

[WILDHOBO]

37x12.5x17 you are correct, it is a E/10-ply.... but
A heavier tire means that there is more rubber, which translates into deeper lugs that provide better traction and thicker, stronger sidewalls. There is still value to running a Load Range E tire on a lightweight off-road vehicle. While the carcass will not be as flexible as an equivalent tire in a lower load range, the air pressure can be lowered to account for this. The reason the carcass is less flexible is because of heavier construction that fends off punctures off-road.
Getting the proper PSI, is a little more tricky with the range E tire, heat is the killer as @ScottBeach mentioned.

My 37x12.5x17 are D rated. That’s why I run 27psi.

 

[SargeDiesel]

My 37x12.5x17 are D rated. That’s why I run 27psi.

I'm guessing 30 psi is going to be the sweet spot for me... but until I do a chalk test... can't be sure. I will definitely have to pay close attention to the heat while figuring it all out though... I would rather run a little high psi and over time wear the center more than run too low of a psi and over heat the tire and have a blowout or wear the entire tire out very prematurely. Just my thinking...anyway.

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