I have a set of 20" Pirelli sottozero winter tires on my PTT, worked great last winter. But - I cannot find anywhere the correct "daily" inflation pressure. Max for these tires is 50 psi/full load which I don't have.
How to figure correct pressure?

 

I would use the pressure recommended on the door sticker and adjust for the actual temp that you would be driving in, ie. one pound plus or minus for every 10 dregree change.