36.5-37" tires. Will ride very stiff with zero ability to use low pressures offroad, with high load capacity. Designed for motorhomes with ultracompliant suspensions.
I'd RATHER ride on 11.00R16 Michelin XZLs (or even 9.00R16s, AKA 255/100R16s) or if 20s are needed due to brakes, 275/80R20 XZLs.
Charlie