Do not trust dealer or cheap air guage.

[FREEZE451]

Any issues? A 12.5 on a 7.5 wheel is pushing it. I am looking for a wheel for my 37” spare and had discounted the spare as an option. I bet a 12.5 on it would be very tight fit under the bed due to crowning of the tire.

None yet! Have about 5,000 miles so far and they are great. Didn't regear either.

I would say under the bed is a super snug fit. I'm not sure if it's %100 seated, but I can try to grab a photo today.

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[Whatscooking]

So why do you say we shouldn't trust the dealer or a cheap air gauge?
The truck comes with high air pressure off of the transport and the dealer usually doesn't change it until it's prepped for sale.

Got her home checked pressure and foundd them high, somehow mine was delivered with 39 in the tires. I didn't know untill Mac pointed out that my dash showes tire pressure. I saw that larger screen has a page that showes all the readings at one time and gave up that mine had the ability to show them also.

 

[Jim_n_Tx]

Isn't tire pressure a function of the vehicle, not the tires?

 

[Gvsukids]

Got her home checked pressure and foundd them high, somehow mine was delivered with 39 in the tires. I didn't know untill Mac pointed out that my dash showes tire pressure. I saw that larger screen has a page that showes all the readings at one time and gave up that mine had the ability to show them also.

Tire pressure is shown on a screen on the dash between the speedometer and the tachometer.

 

[FREEZE451]

Any issues? A 12.5 on a 7.5 wheel is pushing it. I am looking for a wheel for my 37” spare and had discounted the spare as an option. I bet a 12.5 on it would be very tight fit under the bed due to crowning of the tire.

Here are some photos.

 

[PDiddy]

I thought my pressure might be high too. They are at 39 from factory. Mines a rubicon with the 33 M/Ts. When I did a little wheeling with the family I thought the suspension felt really stiff. My first thought was the tire pressure. I also tow a large travel trailer which seems good 39psi. Maybe I’ll try lowering it for my daily driving.

I had 33s on my 4Runner but can’t remember what psi I ran them at. It was a much plusher ride. But that was mostly due to the suspension.

 

[Gvsukids]

I thought my pressure might be high too. They are at 39 from factory. Mines a rubicon with the 33 M/Ts. When I did a little wheeling with the family I thought the suspension felt really stiff. My first thought was the tire pressure. I also tow a large travel trailer which seems good 39psi. Maybe I’ll try lowering it for my daily driving.

I had 33s on my 4Runner but can’t remember what psi I ran them at. It was a much plusher ride. But that was mostly due to the suspension.

Your door sticker would say the correct psi for factory tires.

 

[DLAW]

My JTR with the stock 33 ATs was delivered to me a few weeks ago with 40 PSI. First drive home it peaked to 42. Now that it's colder, 38.

Too high? What PSI "feels right" for the Rubicon AT 33s?

 

[Demo_slug]

Every tire company publishes an inflation guide for every tire they make. It tells you inflation pressure vs rated weight. You take the total weight of the truck and calculate. You should never go below that value.

https://www.toyotires.com/media/3729/application_of_load_inflation_tables_20200723.pdf

 

[JoseQ_80]

Same thing happened to me. First drive with as delivered pressure had the truck wandering all over the road. Showed 39 psi on the dash cold.

Lowered to 34-35 psi and made a noticeable difference. Recommended pressure in the door sticker is 36 psi.

There are some videos on YouTube showing how to use chalk on your tire to see what the correct pressure is for any tire.

 

[Mac]

Around 30 degrees mine are at 36psi cold and after a little while on the highway they go up to 40-41psi

 

[j.o.y.ride]

I brought my Sport S home and drove it for a week before i got out my trusted air guage out that i bought to set air pressure in my motorcycle tires, paid around $40.00 for it. They were set at 39 so i set them to 36. Yesterday we took a 200 mile trip and the difference is very noticeable. Very settled feeling without that dance feeling, softer feel to the ride.
I have 25 years in fleet maintenance maintaining 35 to 40 delivery trucks at a time. When i would put new tires on a truck and not tell the driver they would come to see me explaning how they got the sh!% scared out of them by the truck walking when they took corners too fast. It was discovered that only the very centermost of the tread was touching the pavement with the air psi set to the recommended pressure, 75. Try this by putting down some brown paper and rolling a tire across it and you will see this. I would set the psi to 55 and let them drive it that way untill the nxet PMI and reset to 75.
I am just saying proper air pressure makes a huge difference.

I run at 28 ideally on my 35/12.5. If it gets to 31, 32 it definitely feels like ice skates.

 

[FLUndertaker]

I run at 28 ideally on my 35/12.5. If it gets to 31, 32 it definitely feels like ice skates.

I’m with ya, I run my ridge grapplers at 30. I have a great contact patch. Not sure why folks run big tires rock hard on a light vehicle.

 

[Jeeperjamie]

I’m with ya, I run my ridge grapplers at 30. I have a great contact patch. Not sure why folks run big tires rock hard on a light vehicle.

It's all about the tire, not all tire brands are the same. BFG'S are softer already than most other tires so less air makes for a uneven wear pattern. The JT weighs more than my JKU did also. Mine feel the best between 37-40 on mine,. especially after the added weight with front and rear bumpers and winch.

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