Here's a crop from one of Lehel's photos showing the single rear wheel:
Rims 8.5x19.5 from Stockton Wheel
Tires Yokohama TY 303 285/70 19.5
the manufacturer rates the tires to carry 6345 lbs when tire pressure is 120 lb/sq in so that's about 12,000 lbs per axle
The Fuso FG brochure says the rear axle is rated to carry 9,480 lbs, so the tires have enough capacity.
The TY303 285/70R19.5 is 11.1 inches wide, and 35.4 inches high at 120 psi. The Yokohama Y742S 235/85R16 tires that the Fuso FG comes with are 9.3 inches wide and 31.9 inches tall.
Lehel, do you have any interference problems when the front wheel is turned fully to the side? Did Stockton Wheel give you an estimate of the load bearing capability of the custom wheel?
Yokohama says the Y742S needs 650 revolutions per mile, and the TY303 takes 591 revolutions per mile. That's about 9% less than the Y742S.
Chip Haven