Found this link in a thread at Corner Carvers. Good info.
I’ve only realized in the last year or so that ever since I started tracking cars, I’ve been under inflating DD, tow vehicle and trailer tires. The tire says max cold inflation pressure and I mentally drop that by 3-5psi because the tire might be already warm or because I figured I had to account for the fact that the tire’s pressure would grow a bit when it got warm. Besides, the tire says “max pressure” not “optimum” pressure. I’m just now realizing that max cold inflation pressure means if the tire is reasonably cool, go ahead and fill it to the max. When the tire gets hot on the freeway and pressure grows, that’s ok.