For what it's worth, when I took delivery of my 2011 Ram 2500 it rode much harsher than I remembered from the test drive.
I checked the pressure and the dealership had inflated the tires to their max payload recommendation as it appeared on the Supplemental Tire Pressure Information sticker on the door jamb. 75 front and 80 rear. I figured it was a CYA on the dealership's part in case I went out right away and loaded a truck camper onto it - maybe they were just preparing it for the worst possible scenario.
Anyway, I just let a whole lot of air out of the tires to bring them down to the "Light Load" rating - 65 front, 45 rear, as per the door jam - and all was well.
Edit: After you reduce your tire inflation to the "Light Load" recommendation (which appears on the Supplemental Tire Pressure Information sticker) you need to activate the "Light Load" button on your dash. On my 2011 the "Light Load" switch is
located on the instrument panel above the climate controls. This should light up a "Light Load" indicator on you dash - at least it does on my 2011. If you don't push the "Light Load" button the system will think the tires are under inflated and the Low Tire warning light will come on.
