2019 coleman 264RL tire pressure?

Take whatever it weighs (gvw if you don’t know actual) divide it by 4, look up the pressure for that weight on a chart.
Or go max pressure for the tires on it assuming they’re the proper ones for the trailer, if you’re not willing to look it up.

Most RV trailers come with OEM tires that are just barely adequate to cover the axle ratings when inflated to sidewall pressure indicated.

Unless someone replaced the originals, with a way over rated tire, use the likely 65 psi max. You should have stated the tire size, load rating, and tire max pressure, for best answers.

Even a C-load range tire would be 50 psi, so yes 40 psi is likely low.

Jerry

I would think that you have duel 3500 lb. axles on your trailer. That being said I would hope that you have at least 20575/15 C load range tires on the unit. I had that size tire when I purchased my Trail Blazer and Coachmen called for the tires to be inflated to 50 psi. My Trail Blazer had a GVWR of 7900 lbs. which is just a little more than your Coleman.

I would try to find a tire mfg. pressure guide and go from there. It would alshelp to have the rig weighed in order to cut down on the confusion.