Air down/up - safe PSI to air down to on rocky terrain?

[AZTacoStand]

Hey, going out this afternoon and wondering -

For rocky terrain where you want to air down, with non beadlock wheels what is a safe PSI to air down to?

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[magicbenjils]

It depends on your wheel/tire combo: typically a smaller wheel with a taller sidewall tire can safely air down more than a lower profile on a larger wheel.

I’m running 285/70r17’s on the stock TRD OR wheels and have gone down to 20 psi in rocky terrain without issue. Could probably go lower, but 20 seems like a good balance of a noticeably more comfortable ride off road and better traction, without having to worry too much.

 

[lauren01]

On stock Trailhunter wheels and its humble Goodyears 265/70/18, the setup performed well the one time we aired down so far since buying the truck.
We were at 19 or 20 psi for half a day going up and down dry gravel, sandy and rutted steep mountain roads and washboard on the flats. I feel like we could’ve aired down a little bit more but I was comfortable around 20.
I see Method Bead Grip wheels in my future. But no hurry while my money is worthless.

 

[Pappy]

It depends on how rocky. I run 285/70-17 at 12-15psi depending on surface. Usually if it's just a dirt road with washboard I'll start at 20psi, and adjust down if I need to.

 

[Bcphoto3]

Running 285/70/17 Falken AT4w on Method 703 wheels.. In west TX, while pulling overlanding trailer on 4WD roads we went down to 18 without an problem.. I think could easliey go down to 12-15.. Most difficult thing was figuring out the TPMS settings so the truck was yelling the whole time to air up the tires!

 

[Wife bought my 24 TRD]

You're question is subject to the trucks weight, tire combo, and the environment that you wish to conquer.
I run a 33x9.5, or in metric a 255 80 17 and have safely aired down to 15psi without beadlock rims in sandy and muddy conditions. In rocky conditions I air down to 20psi.
The reason I only go down to 20psi in the rock 🪨 is because my truck weighs roughly 2000 pounds over the stock weight. The weight makes up for the 5lbs difference.
I highly recommend buying a good air compressor, it makes life easier. I chose ARB twin with a zroadz bracket.

 

[YUT]

I slightly disagree here. We have been up and down the $$ on compressors and now we ended up on a Milwaukee 18v comp and it's works wonders.

As for psi this depends on load, GVW, terrain, and more. We have been down as low as 5psi but again it varies. There are some good YTs on this topic and rule of thumb is air down to get grip than up/down from that point to retain grip. Floattion is not a factor at this point.

You're question is subject to the trucks weight, tire combo, and the environment that you wish to conquer.
I run a 33x9.5, or in metric a 255 80 17 and have safely aired down to 15psi without beadlock rims in sandy and muddy conditions. In rocky conditions I air down to 20psi.
The reason I only go down to 20psi in the rock 🪨 is because my truck weighs roughly 2000 pounds over the stock weight. The weight makes up for the 5lbs difference.
I highly recommend buying a good air compressor, it makes life easier. I chose ARB twin with a zroadz bracket.

 

[mtbocoee]

Hello Bill,

So you decided to stay with 33" tires rather jump to 34" with the 285/75/17? What are you running C or E rated version?

Tires are on my list to address this summer. Trying to decide if I should stick with stock TH wheels and increase tire width and size or go the Method 703 route for more peace of mind on air down. I did run the stock wheels and tires at 20 psi for 100 miles on the White Rim without issue.

 

[lauren01]

Running 285/70/17 Falken AT4w on Method 703 wheels.. In west TX, while pulling overlanding trailer on 4WD roads we went down to 18 without an problem.. I think could easliey go down to 12-15.. Most difficult thing was figuring out the TPMS settings so the truck was yelling the whole time to air up the tires!

Do tell! I thought that the TPMS warning was something I had to live with, but what can you share about this? Go through the infotainment to find a setting use a scan tool? I don’t have a TPMS kit.

 

[Bcphoto3]

Hello Bill,

So you decided to stay with 33" tires rather jump to 34" with the 285/75/17? What are you running C or E rated version?

Tires are on my list to address this summer. Trying to decide if I should stick with stock TH wheels and increase tire width and size or go the Method 703 route for more peace of mind on air down. I did run the stock wheels and tires at 20 psi for 100 miles on the White Rim without issue.

Went with E load simply becuase of pulling 3500 # overlanding trailer (TetonX). Decided on 33” just so no speedometer discrepancy..

how was the White Rim Trail? Really wanting to do that with the trailer.. Just a little concerned about the switchbacks.. I would be in real trouble if I got stuck somewhere out there as have a number of friends that are NPS rangers in Canyonlands that I work with..

You live close by, whcih should get together sometime when you are back and compare notes..
Bill

 

[mtbocoee]

You live close by, whcih should get together sometime when you are back and compare notes..

Yeah, hopefully we can meet sometime later this year. We can continue conversation of line as I have your email from previous discussions. Just FYI my Dobinson's 21 & 22s just arrived today after four month backorder so our truck will soon be aligned on springs.

 

[lauren01]

Do tell! I thought that the TPMS warning was something I had to live with, but what can you share about this? Go through the infotainment to find a setting use a scan tool? I don’t have a TPMS kit.

I slightly lied. Just looked at my XTool D8W manual. The tablet has TPMS test and reset functionality.

 

[Mitch33]

I ran 20 PSI on this road after running street pressures for a while and it certainly improved ride quality and traction. That was with stock TRD Offroad wheels and tires. On the dunes and beach I usually run 17-19 PSI. I use this viair compressor that I got on sale a couple of years ago for around $80.

Hope you had a fun time!

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