I'm curious why you ran at 55psi.
On your rig, put the full 80psi in those erated tires. You are going to be pleasantly surprised how much less wobble the TT has while pulling. It will fill much more solid behind you going down the road. The tires will age out long before you wear them out.
That's a lot of trailer and you need some reserve capacity on the tires to allow for uneven loading, and speed.
Don't sweat the tread wear. The tires will age out long before the tread is gone. Go with 80 psi and the extra capacity. IF the tread wears more in the middle, which I doubt, it will be so slight as to be inconsequential.
Good smack on advise.
The benefit of the 80 psi E tire over the 65 psi D tire comes only at those higher 80 psi pressures.
Having pulled and used dozens of tires on trailers I've found 80 psi E tire is a heavy tire and will run hotter at those derated 65 psi pressures than the D tire.
Also the E tire at 80 psi stands up to side stress much better than at 65 psi on that 35' 9500 lb trailer.
Other than new tires your not gaining much.
