I just took my first trip with these:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Trailer King ST Radial Trailer Tire - 225/75R15 117L Load Range E 10 Ply Rating
Probably 1,700 miles round trip, 3,400# car in 24ft trailer with Drag Week supplies.
We drove a close to 75 mph most of the trip and did not have a bit of trouble.
Last year we looked like a Nascar pit crew changing so many trailer tires just going to St. Louis from Tulsa.
Bill