Originally Posted by kandl
The vehicle's (TT) recommended cold inflation pressure is in fact the max inflation pressure for the tire/s.
That is probably also with your trailer's GVWR, i.e. the maximum weight the trailer is rated for when fully loaded. Depending on your trailer and your cargo, the rig might weigh well under what its rated for. So there is room for adjustment down from max psi, but only if you know your trailer's weight and know what you're doing with inflation ratios. Otherwise, max recommended psi is probably best practice as mentioned.