On tar 36psi front and rear, except when I'm towing then I up the rear to 38-40psi depending on what is in the back - I used the 4psi rule to get to these pressures. On dirt I drop 10psi, and on sand I will start at 20psi and lower as needed.
I will add that I won't be buying these again. While they have done almost everything that I've asked them, two of them (out of eight) have become impossible to balance 100% correctly, and while they have more than 50% life left (they give excellent mileage), I can't rotate them because one gives too much vibration as a steering wheel and another can't be run in the opposite direction without also vibrating quite badly.