i had e rated nitto terra grappers and couldnt stand the ride at the 40 psi min. that they recomended. (i called nitto about the min air pressure)
i took them back to NTB under their guarantee and exchanged them for the P rated extra load. the max air is 34 psi and will handle the normal loads i run and the ocassional heavy ones.

but the shocks seem to need to be replaced. small bumps the truck vibrates but the bigger bumps the truck handles fine. i am just under 38k miles.

 

Those are Cooper Winter treads on my F150 Heavy Half. We're talking 8200 GVW vehicle these are used on during the winter months. I figure if Cooper uses that setting then it must be ok.

 

Again, what is the max pressure listed on the side wall. If you are over that, it is overinflated. Also, I would never use a p series tire on an 8200lb GVWR F150. The come standard with LR E tires. for a reason

 

i got 33" e rated tires. i run em at 35...smooth so far

 

Too low. Good way to have a blowout.

 

really? they look just fine on the truck. not squishy or anything...what should i run em at

 

no less the 40psi. at 35psi it must feel like your truck is on marbles. i run 43-45psi in my pro grade silent armors on my 03-F150. i find that to be the best for me. wear is excellent as well and rides fine.

 

Depends on what the max pressure and weight rating is on the tire. If a max of 80, and a weight rating of 4000lb or over then you can run at 40. If lower, 45 or 50 would be better. If a max of 65, 45 would be about right.
One of the worst things you can do to a tire is run too low a pressure. It damages the tire itself at highway speeds due to heat buildup. That eventually will cause a blowout or tread separation.