What kind of tire PSI would or do any of you run towing? I've bought another 5th wheel. Advertised weight is 5800lbs empty and dry. Not much squat to the truck hooked up. Wondering what air psi to run in rear 20 inch tires.

 

Max load rating is generally available at max PSI. If you are still running the crappy stock tires I'd start with the pressure on the door jamb and work your way up a few psi at a time if it feels like the tires are swaying.

 

I'll be switching to "real" LT (light truck) tires as soon as the factory passenger radials wear out. The LT tires have max PSI around 80psi, whereas the passenger radials are around 40psi, and have whimpy/soft sidewalls. I'll have to put up with a little lateral movement while towing until the swap. Plus, they just look better. Of course, the LT tires will ride a bit rougher.

 

The max psi on the door is 35. Thats NOT whats on the tire. Its in the 40s. I do not want to go to a LT tire. Ride would greatly suffer. Most of the time this truck won't have the trailer hooked. Just to a where I'm going. Guess while towing I'll go to the MAX cold psi on the tire(rears) Fronts I'll stick with 35psi. Hope it dosen't cause the air psi warning to go off.

 

It will. Mine goes off when I have around 45 psi - only when I'm loaded heavy, you just learn to ignore it. I don't run LT tires either but I do have some P tires that have a very high load rating (17" rims).

 

i fill my 17" stock "P" tires up to max cold when towing my heavy trailer. it helps a bit.

 

I've ridden in my friend's Outdoorsman, which has 80 psi tires (LT) on it, and compared his ride to mine ( 40 psi passenger tires). They're essentially the same truck, with different tires. His ride might be a bit more firm, but it's not harsh or like a "coal cart". I don't think the ride "greatly suffers", and I look forward to putting LT tires on mine. I also think his sits just a tiny bit taller due to the sidewalls not squishing like the passenger radials.

 

I filled mine to 38 psi this last weekend when I was pulling 6000 pounds with a bumper pull. I only pulled it about 400 miles but it seemed to do just fine, they were squatting a little, they matched the front.