I used to think that since I never hauled anything, I might as well lower the tire pressure for a better ride. That started when I put 4" lift on an 89 Toyota P/U with 33" BFG M/T, didnt want to wear out the center at 15K miles....so I ran 15 psi in front and 10 in back, just enough for the sidewall to have a nice curve.
Two trucks later, I had a 98 Z71 with a 4" lift, I ran 285's on 16x8's and used that same thinking, 35 front, 30 rear psi for about 15k miles. One day I had it alligned at a very trustworthy shop here in Marion. They noticed tiny sidewall crackes....from heat as a resault of too much flexing.I was ruining my tires from the sidewalls to enjoy a smoother ride. They inflated the 285's to 60 psi front and rear and suggested I keep them there, at the tires recomended psi.
I was amazed at how much rolling resistance I was constantly fighting. With the correct psi, it was a whole diffrent truck.
I run 65 psi in the Firestone's on my 01 now, it may ride rough but if I want to haul, I dont want to get out the air compressor and guage everytime. Besides, Iv got a work car I drive to work if i dont need the 8' bed.