[gearhead]

If it's a trailer tire I air it to max pressure on the sidewall. I believe that is what Carlisle recommends. Really doesn't matter to me what the load is as long as I'm not overloading the the trailer. I have a tandem axle boat trailer that's rated for 4,000#, mostly I think to avoid brake requirements. I have owned that boat & trailer since bought new in 2014. I have never weighed it and probably never will. I did step up a load range to LR "D", I think, 65psi. I air them to max and get on down the road. The 5th wheel has H rated and calls for 123psi which is what I run them. My Ram dually I run at what my yellow sticker says when loaded. When unloaded I drop the rears down to 45, maybe 40, maybe 42.
Nobody but me ever airs up my tires.
I know common sense isn't very common, but..