I have a 64 Globetrotter for which I'm buyin 16" steel wheels and commercial Michelin XPS-RIB 225 75 16 tires. The XPS-RIB's are identical in height to the 700 15 as verified by Ed in Michelin's commercial tire dept. The new tires are .9" wider (.45" inside .45"outside) than the 700 15's. The XPS-RIB has a steel sidewall (stranded), a high mileage rating, and it could be inflated to 80 lbs. Its and E rated tire. I plan to run it at 60 lbs. for my single axle.
The cost of one tire is around $170 from COSTCO or Discount (a tough pill to swallow) but, me and my trailer are worth it. I bought the wheels at Southwest Wheel (Derric Sweden) for $189.49 (3 wheels) plus shipping. I specified (per Arlen) load range, circle dia. etc. for the wheels. I also plan to check dynamic simulation of static load (upward and inward travel of the tire) to assure adequate clearance from a width standpoint. Altogether I will have about $740 invested in wheels and tires.
If I keep the tires protected when not in use (to prevent dry rot) and my $700, I plan to get many years of safe performance (no blowouts) and 60,000 miles from the tires. I may expire before the tires but, my silver thermos will have good shoes.
My floor is ripped up, the toilet is ripped out, the old power system is ripped out, and the plumbing doesn't work; and I'm buying tires! Do you sense something is wrong?