My 2015 Keystone Raptor came with Trailer King 235/80/R16 tires. I was skeptical but figured I'd run them till one failed and then replace them. At about 5100 miles on a 1800 round trip in June they...
Your story mirror what thousands of other trailer owners (rv and non rv) have found when they have tire zippers......tread separations......complete tread loss/etc with the light weight ST E tires. A commercial grade all steel ply carcass 4080 ST G is a good choice for 7k axles or max loaded 6k axles.