Originally Posted by Highway 4x4
The tires were designed to run at 80. I run at a few pounds of that, checked cold. TT tires have a max of 65 and I run them at 65, checked cold. They run cooler at the max and better MPG.
Not all are the same and running max psi without max load just makes for a harsh ride for no reason.
I have a 2012 Ram 2500 as well and after much experimenting, mine likes about 65 in the front to carry the diesel all the time. 45 in the rear when empty (press the low tire pressure button) and about 75 when towing.
Keep in mind the tires are an important part of your suspension and that function comes from the correct tire pressure. Also, tires are your #1 safety feature and the more pressure you run, the smaller the contact patch (traction).
Keep a close eye on your tire wear over time... If the shoulders wear: pressure is too low; If the center wears: pressure is too high.
I have easy access to an air hose, so I do actually always change my tire pressure in the rears between 45 and 75 if empty or towing and loaded.