Where are all the Trail-Lite motorhome owners? This thread was a "hot topic" for many months (years). Any new buyers of these discontinued units won't have a clue that this thread exists.
I spent some money on new tires for my unit. Cost right at $1,000 for six (6) new Firestone Transforce HT (load range E) mounted and balanced and old tires disposed of. The installer told me that he had never seen such old tires in that good of shape - no weather cracking or uneven wear. They had not spent that much of their life in the hot sun. I just felt that now was the time to replace.