2008 Jayco 17c ex-port. For me there is significant camper usefulness. The OEM tires, ST185/80/D13 are legal and fine if they last a lifetime. If I recall, they are rated at 1,660 lbs. x2=3,320 with the remaining 180 lb coming from the roughly 300 lb on the hitch. The problem is they do not last a lifetime and cannot be found in stock in at least 8 states where I've had failures or wanted to get a spare. It is a three day order item. That makes it a poor choice.
The alternative in that size is the radial version which is sometimes available. It took 3 states for me to find 3 tires, but they are rated at 1,480 (memory), 180 lbs less than the bias ties and throw the belted tread off in about 2,000 miles. In my case the thrown belt did $350 damage to the camper black water system.
Thus 14" radials at 1,740 lbs (memory).