Redhawk,
Given that the "chart" Rickst29 included in his reply (above) is
identical to the pressures for wheel-weights in my Maxxis chart (linked to above), those ratios probably apply to other tires as well. Our expensive Maxxis tires are likely little different from Marathons or other ST tires in terms of strength or durability.
I too will be interested in hearing if others have actually weighed their TMs (or accurately estimated their weights) and adjusted tire pressures down to as low as the charts seem to call for.
John
TM: 2005 2431KS
Tow Veh.: Ford Expedition
WDH