Here are the payload ratings for the Crew Cab with Diesel:
S: 4x2, 2,091 pounds; 4x4, 2,004 pounds
SV: 4x2, 1,924 pounds; 4x4, 1,838 pounds
PRO-4X: 4x4 only, 1,733 pounds
SL: 4x2, 1,674 pounds; 4x4, 1,588 pounds
Platinum Reserve: 4x2, 1,676 pounds; 4x4, 1,470 pounds
Fully loaded Titan XD has only 1,470 pounds payload. That puts it into 1/2 ton territory.