Best Tire Pressure for Comfort/Wear/Mileage for Stock 33" A/T Tires

[van_tri]

I just bought my JTRX in January and I've been running the stock 33" A/T tires at the door jam recommended 37 PSI
As we head into hot weather, I find it hard to believe a cold reading of 37 PSI is going to be comfortable or wear appropriately.
What have people reported as the right year-round PSI for the stock 33" ATs?

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[wcberry]

Follow the OEM recommendation. Add air in the winter as needed and remove air as needed in the summer.

 

[van_tri]

Was hoping someone had already chalk tested and either confirmed or refuted the manufacturer recommended 37 PSI. My JKU was spot-on at 34 PSI for same size Toyo A/Ts

 

[Sigz]

I run my 285/70/17 AT3Ws at 29 PSI and I helped smooth out the ride considerably.

 

[MT1]

I've not chalk tested. 32 or so is where I no longer see daylight under the outer tread blocks and have a smoother ride on street. But, running at that pressure costs about 2 MPG, end up averaging 17 instead of 19.

 

[van_tri]

Interesting,

I've not chalk tested. 32 or so is where I no longer see daylight under the outer tread blocks and have a smoother ride on street. But, running at that pressure costs about 2 MPG, end up averaging 17 instead of 19.

I was just replying to @Sigz about mpg difference and wondering about contact patch in the middle. What's interesting is that I took delivery to my house (via a driver) from the dealer and the dealer had all the tires pegged at 32 PSI.

 

[Sigz]

Interesting,

I was just replying to @Sigz about mpg difference and wondering about contact patch in the middle. What's interesting is that I took delivery to my house (via a driver) from the dealer and the dealer had all the tires pegged at 32 PSI.

I haven’t chalked tested yet - and my mileage literally hasn’t gotten worse or better. Avg about 18.9 on my last fill up (although engine, gear ratio, driving location, etc will all play a part in that)

 

[Mr._Bill]

Was hoping someone had already chalk tested and either confirmed or refuted the manufacturer recommended 37 PSI. My JKU was spot-on at 34 PSI for same size Toyo A/Ts

It varies with vehicle. If you want chalk test results, you have to do your own. The manufacturer recommended PSI is a general compromise between comfort, wear, and economy. Lower the PSI for a better ride, raise it for better economy.

I have the 20" wheels with street tires. I run at 39psi cold, which gives me up to 45psi when on the highway. I'm more concerned with economy, but ride comfort is still good.

 

[jav_eee]

Follow the OEM recommendation. Add air in the winter as needed and remove air as needed in the summer.

Unless you don’t have the factory original tires anymore.

(For anyone searching this topic).

 

[ShadowsPapa]

Was hoping someone had already chalk tested and either confirmed or refuted the manufacturer recommended 37 PSI. My JKU was spot-on at 34 PSI for same size Toyo A/Ts

Chalk test someone else does won't necessarily translate to YOUR truck. It varies with the weight of the vehicle.
I found I always get the best life and wear and traction at the recommended pressures.

Unless you don’t have the factory original tires anymore.

(For anyone searching this topic).

Yeah. In the case of the General A/Tx tires I put on my Overland, i contacted the company themselves. They asked about the weight of my truck, the original tire size and recommended pressure for those tires on my truck, then gave me a figure. And it worked great.
The chalk test had my tires wearing weird on the edges so I went back to the companies recommended number for my truck and they went 47,000 - and still had life when I traded the truck in (29,000 on the 2022, and they were on for 18,000 on my 2020)
Goofy thing was - the chalk test had things looking good at both 32 psi and 37 psi! It was very inconclusive and I ran it several times.
I guess it also doesn't account for the tire "Squirm" and flexing and dynamic diameter of the tire as you drive at speed.

 

[van_tri]

..... Goofy thing was - the chalk test had things looking good at both 32 psi and 37 psi! It was very inconclusive and I ran it several times.
I guess it also doesn't account for the tire "Squirm" and flexing and dynamic diameter of the tire as you drive at speed.

Precisely why I dare post a "tired" topic. I did the chalk test (so many times) on my JKU and 34 PSI seemed best for the results I could determine while also comparing forum members' results with the exact same type Toyos. All factors considered ... I rank "wear pattern" as my top priority because of the safety, longevity and also the noise uneven tires make. The fuel savings of an extra couple mpg would be great but, in reality, it probably equates to savings of the cost of one tire over 40,000 miles.

 

[Janster]

Follow the OEM recommendation. Add air in the winter as needed and remove air as needed in the summer.

I do the opposite…… remove air in winter (softer for traction) and go back to 37 or add air in summer.

 

[Mr Miami]

It varies with vehicle. If you want chalk test results, you have to do your own. The manufacturer recommended PSI is a general compromise between comfort, wear, and economy. Lower the PSI for a better ride, raise it for better economy.

I have the 20" wheels with street tires. I run at 39psi cold, which gives me up to 45psi when on the highway. I'm more concerned with economy, but ride comfort is still good.

You said it all when you used the word "compromise". The manufacturer uses numbers that represent a good compromise in the expected usage of the tires. Deviations from that will favor one factor over others. It's not rocket science, but just adjusting things to get the most perceived benefit from the tires.

 

[Reddog]

Chalk test someone else does won't necessarily translate to YOUR truck. It varies with the weight of the vehicle.
I found I always get the best life and wear and traction at the recommended pressures.


Yeah. In the case of the General A/Tx tires I put on my Overland, i contacted the company themselves. They asked about the weight of my truck, the original tire size and recommended pressure for those tires on my truck, then gave me a figure. And it worked great.
The chalk test had my tires wearing weird on the edges so I went back to the companies recommended number for my truck and they went 47,000 - and still had life when I traded the truck in (29,000 on the 2022, and they were on for 18,000 on my 2020)
Goofy thing was - the chalk test had things looking good at both 32 psi and 37 psi! It was very inconclusive and I ran it several times.
I guess it also doesn't account for the tire "Squirm" and flexing and dynamic diameter of the tire as you drive at speed.

I have chalk tested and never found it valuable or worthwhile on my tires. The load on the tires makes a big difference. The pressure needs to change as the load and use changes. What really matters though is the safety of the tire while being used a particular way. Too many people get caught up over thinking ride vs pressure vs traction vs wear. If you haul loads or tow heavy loads the pressure needs to be up at manufactures numbers. The chalk testing in my view is a waste of time. We spend countless dollars adding things and weight to our JT’s and agonize over what is the perfect tire pressure. There isnt one.

 

[Mr Miami]

I have chalk tested and never found it valuable or worthwhile on my tires. The load on the tires makes a big difference. The pressure needs to change as the load and use changes. What really matters though is the safety of the tire while being used a particular way. Too many people get caught up over thinking ride vs pressure vs traction vs wear. If you haul loads or tow heavy loads the pressure needs to be up at manufactures numbers. The chalk testing in my view is a waste of time. We spend countless dollars adding things and weight to our JT’s and agonize over what is the perfect tire pressure. There isnt one.

Yes, we agonize over tire pressure. Maybe be need another "which brand of oil" is the best to complement the tire pressure debate.

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