28 / 25 PSI - Are you kidding me ?

[SargeDiesel]

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. (37x12.5x17)
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.

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[bleda2002]

I run 28-30 on 37's and 39's, no issue and even wear. Both the wife's 4xe wrangler (similar weight to our trucks) and my truck and been served well by it (and the chalk test looks good there).

Anything less than 28 and the steering wheel starts getting a bit heavy in parking lots, and over about 32 it just gets bouncy.

 

[SargeDiesel]

I run 28-30 on 37's and 39's, no issue and even wear. Both the wife's 4xe wrangler (similar weight to our trucks) and my truck and been served well by it (and the chalk test looks good there).

Anything less than 28 and the steering wheel starts getting a bit heavy in parking lots, and over about 32 it just gets bouncy.

Thanks for your input. I will wait until first thing in the morning and lower the pressure to 30psi and work my way down from there.(don't want to make a huge drastic change at once, might blow my mind and give me a false sense of WTF... LOL)... scale weight and chalk test still in the plan.
Thanks

 

[TARHEELKIDD]

Chiming in to confirm as well. I am running 37 x 13.5 x 17 at 28 cold PSI. It jumps to 30 on very hot days. It is perfect. I even reached out to the tire manufacturer(Nitto)as I thought 28 was too low. I provided them my make and model as well as their tire info I am running and they confirmed that It performs best at 28 to 30 cold PSI and do not inflate higher the 30 PSI unless carrying heavy loads or towing.

 

[SargeDiesel]

Chiming in to confirm as well. I am running 37 x 13.5 x 17 at 28 cold PSI. It jumps to 30 on very hot days. It is perfect. I even reached out to the tire manufacturer(Nitto)as I thought 28 was too low. I provided them my make and model as well as their tire info I am running and they confirmed that It performs best at 28 to 30 cold PSI and do not inflate higher the 30 PSI unless carrying heavy loads or towing.

Thanks, great confirmation.... is always appreciated. ?

 

[SargeDiesel]

@bleda2002 , @TARHEELKIDD just glad I'm catching it at a low mileage (basically 5k) Doesn't look like it has caused any damage or real excessive wear... jumping down 6psi or so seems like it might take some getting used to though.

 

[TARHEELKIDD]

Thanks, great confirmation.... is always appreciated. ?

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

 

[aprez27]

Never went above 30 on any of my Jeeps, all had 35's but that doesn't really matter.

 

[Orange01z28]

You're overthinking it

Drive where it feels best

I stay around 35 cold

 

[bd100]

do not inflate higher the 30 PSI unless carrying heavy loads or towing.

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.

 

[jay21mojave]

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

 

[KSP938]

I stay at 32 in the summer and 29-30 winter. 21 Mojave.

 

[ScottBeach]

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

 

[MJRSC]

I am second guessing everything now ha.

I messed with it plenty and settled around 33 being good on 37" KO2's. I have over 5k mi of wear with no issues.

 

[NewGladdyOWNR]

35 cold for me, runs around 38/39 hot. Trucks seems to feel the best at that PSI for me.

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