2002 F250 PSD with cab height bed cover. LR E tires.
2016 Ram 1500 CTD with normal bed cover.
I always ran my truck fronts at 75 and rears at 80 whether towing or not. Never had a problem with wear or rough ride.
Trailer: 2004 Sunnybrook Titan 30FKS. Came with 15" LR C tires. Ran those at 50psi for 5 years. Changed to Maxxis LR D for another 5 years at 65psi. Changed to Maxxis LR E. Ran those until we quit towing last year at 80PSI and they are still on the trailer today.
I have never had a single tire problem on either the truck or trailer and, as you can see, have always run my trailer tires at the max. sidewall pressure as recommended by many manufacturers and tire experts. If I were still towing today, I would do it the same way! :B
Barney