I can't imagine small trailer tires being rated for 80 or so. The ones on my RV are rated at 65.
Very true. Worse, it seems like the factory tires on small trailers are
usually 2 ply, cheap and prone to blowouts if used beyond their ratings.
I was pleased to see that the previous owner of the little camper I
bought last summer had replaced the original tires with Michelin 4 ply
tires with a 6 ply rating. Most important thing is to make sure they
are properly inflated. Not a guarantee against failure but more peace
of mind when cruising down the highway doing 80 mph or so. :-)