My tires run at 27.5 PSi at all times, they're rated for 35 psi, but I'd rather sacrafice the gas milage for a working liver when I get to my destination.

My 31x10.5's are rated for 50psi, doesn't mean that's the right pressure to run them at. New I had them at 18psi and now that they have better sidewall flex I run them around 22psi and 10-12psi is good in the snow so far, haven't tried lower yet. General offroad work sees them at 14-16psi.