What should my tire pressure be?

[Oneshotlucky]

Looking for a bit of advice! I have BFG 34x10.5x17 D rated on my JT. What’s the best cold pressure should I be at? It’s my DD don’t tow I only load it up when camping, hunting and fishing. When tires were installed lift shop set pressure at 36 psi. Just checking if that should be right?

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[Lunentucker]

I run my stock 33 Falkens at 35 by my gauge and it's 33 on the dash.
Chalk test is best but you can move up or down a pound for comfort and it shouldn't matter much.
I do know that 37 on the stock tires is too much.

 

[ShadowsPapa]

Looking for a bit of advice! I have BFG 34x10.5x17 D rated on my JT. What’s the best cold pressure should I be at? It’s my DD don’t tow I only load it up when camping, hunting and fishing. When tires were installed lift shop set pressure at 36 psi. Just checking if that should be right?

Probably close, but the best for your truck and load may vary because the truck's weight will vary. Unless another truck is the same weight as yours, give or take, the ideal may vary.
Based on the experience with my tires, that might be a good starting point. Check wear pattern, ride (you'll know if it's too much) and try the chalk test (but don't get hung up on a couple PSI)
Use Bing or Google and look for tire wear patterns - that will alert you to whether or not the PSI you are using is right for those tires on your truck.

 

[XraytecH]

 

[Mjolnir]

Chalk test is the only way to really narrow that down and get to where you need to be. Anyone can give you starting points. But chalk test will give you real answers.

 

[ShadowsPapa]

Chalk test is the only way to really narrow that down and get to where you need to be. Anyone can give you starting points. But chalk test will give you real answers.

I found that my stock H/T tires were sitting good at the factory 38 - but 39 and up was high (dealer had 41 in them) and they were still good according to chalk test as low as 35 and yet when I tried running them that low it was showing some abnormal wear.
I ran then at 38 and they wore perfectly even (until I sold them)

When I ran the Rubicon take-off Falkens, testing agreed the typical 36 was good. The chalk patterns were perfect straight across with 36 cold. (again, on my truck, my truck's weight)

Then when I tried these Generals, it indicated I should be 33 or lower - but actual driving shows that low wears the outer edge. That was just waaay too low, even just looking at them they looked like the sort you go up to someone and tell them they'd better air up their tires.

The chalk testing showed the outer ribs weren't touching enough at the advised pressure.
The consumer engineer on the phone said I should be running 35-36 for the weight of my truck. And that made sense based on the square inches of rubber on the ground. For some reason the chalk test just didn't work for these Generals. The outer edges are showing wear and yet the chalk test indicated otherwise, that they'd not be touching pavement.
It was also interesting that I could change the pressure a good 4 or 5 psi and see no difference in the chalk test pattern on these tires.

 

[Mjolnir]

I found that my stock H/T tires were sitting good at the factory 38 - but 39 and up was high (dealer had 41 in them) and they were still good according to chalk test as low as 35 and yet when I tried running them that low it was showing some abnormal wear.
I ran then at 38 and they wore perfectly even (until I sold them)

When I ran the Rubicon take-off Falkens, testing agreed the typical 36 was good. The chalk patterns were perfect straight across with 36 cold. (again, on my truck, my truck's weight)

Then when I tried these Generals, it indicated I should be 33 or lower - but actual driving shows that low wears the outer edge. That was just waaay too low, even just looking at them they looked like the sort you go up to someone and tell them they'd better air up their tires.

The chalk testing showed the outer ribs weren't touching enough at the advised pressure.
The consumer engineer on the phone said I should be running 35-36 for the weight of my truck. And that made sense based on the square inches of rubber on the ground. For some reason the chalk test just didn't work for these Generals. The outer edges are showing wear and yet the chalk test indicated otherwise, that they'd not be touching pavement.
It was also interesting that I could change the pressure a good 4 or 5 psi and see no difference in the chalk test pattern on these tires.

I agree that chalk test isn't "God's word". Obviously you still gotta tweak but it gives you a damn good foundation based on the weight of your vehicle. No one else can really give you that unless they have the same configuration.

 

[ShadowsPapa]

I agree that chalk test isn't "God's word". Obviously you still gotta tweak but it gives you a damn good foundation based on the weight of your vehicle. No one else can really give you that unless they have the same configuration.

Yup.
It's a very solid basis for a starting point.

Anything else is just semi-random numbers.

All I could possibly give is based on the weight of my truck and the exact tires I have.

 

[Bluedog]

The recommended cold tire pressure for your BFG 34x10.5x17 D rated tires can vary depending on the weight of your vehicle and the load you are carrying. However, based on the information you provided, a cold tire pressure of 36 psi should be appropriate for your Jeep JT as a daily driver with occasional camping, hunting, and fishing loads.
https://drivingpress.com/category/blog/

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