swathdiver
Full Access Member
42 PSI just allows the tires to exceed the rear axle's load capacity and that is what BFGoodrich currently recommends for the 1/2-ton Suburbans. Previously their recommendation was 50 psi. A 3/4-ton with the same 265-70-17 tire in an E-Load has a door sticker calling for 50 PSI up front and 60 PSI in the rear.
I ran mine in the 30s and low 40s when new and experienced even though rapid tire wear. I bumped them up to 50 psi and the wear all but stopped but eventually started to wear a little more in the center, about 1/32nd less after 30K miles. I keep them at 47 PSI cold now; all around.
FYI, 42 PSI is plenty to haul a load, the tire's capacity at 42 psi exceeds the 4200 pound axle capacity (2150 per tire).
