Speaking of tire life for high mileage "consumer level" trailers, I was talking to a guy that is one of the owners of a trailer company while at a horse show this summer. They are fitting GY Wrangler HT ( LT ) tires to their trailers. They have also used Hankook LT tires. His comment was the Hankook tires worked well, lasted around 50K miles for a few of his customers, and the GY is lasting 80K or so, also working well.
Another anecdotal data point here, I am approaching 40K miles on my Kumho 857's ( "commercial LT" ) on my travel trailer, and they have about 65% of their original tread. These are lightly loaded though. This trailer only weighs 4100 pounds and is tandem axle.
