I actually have never noticed this, which is embarrassing, but should I adjust the tire PSI when the truck is loaded up? My tires are rated at 65psi cold. It was set at that when unloaded. However, with our toy hauler and approx. 1000lb of tongue weight, the PSI jumped to 75. Should I air the tires back down to 65?

 

Really when hauling things look at the load range of your tires. Generally all 10 ply are load range d and e, I'd take it down to 70 for a little bit of a better ride and as long as your tires are in the correct loss range for what your pulling your good to go

 

Tire pressure does not change when you put a load on it. You likely noticed an increase from being HOT.
Good example...You air your spare tire when it's off the truck and when you put it on the truck, it's pressure remains the same.

Cold PSI is the MAX PSI rating when cold and is the MAX PSI rating for the MAX Load capacity(weight rating of the tire)
So, in other words, in order to haul the most amount of weight the tire can handle, you need to inflate to the MAX PSI.
You can under inflate if the load isn't as much.

I run 35psi empty, loaded and while towing. I never change my tire pressure. My tires are rated at 50PSI Max I believe but since I never run them at or near their max weight rating, it's perfectly safe to keep them at 35psi.

 

Hmmm maybe Americas tire inflated them according to the 80psi door sticker. Tires are rated at 65psi. I'll just readjust back down to 65psi with the trailer hooked up.

 

ahhhh...ummmm I thought you said they were only rated for 65psi MAX? That means they should never be inflated above 65PSI when cold. Like I already said, when the tires are hot, the air will expand and give you a higher reading. This is why your only suppose to check tire pressure when cold.

The tires at their max PSI will be stiffest giving you the roughest ride. I'd suggest airing down some for everyday use. I run 35psi for my 1500 series. I would say dont go below 50psi for a 2500

 

Tire stickers on door jams only reflect the stock tires, p rated tires should never be inflated past 35 psi empty or loaded. E rated tires are ten ply and even than I don't run mine over 60 psi loaded.

Running psi at max kills tire tread depth..

 

Thanks for the input. I just needed quick answers as I was getting ready to head out to the desert.

FYI, it was on a F350 super duty. With the nitto terra grapplers. I believe the door sticker PSI exceeds these AT tires and Americas tire goes strictly off of the Factory tire ratings, which is dumb. I believe my Dad recently had them rotate the tires. I just aired them down to 65psi for the trip.

I actually ONLY checked the tire pressure when they were cold, with the trailer hooked up, so I assumed the rear tires were at the same PSI as the fronts. I had 75 rear, 65 front. All in all, I think the pressures were off from the get-go, confusing me.