It all comes down to, what is your objective and how much are you willing to pay.
I add 3 years and over 15,000 miles to a used TT before I replaced the 7 year old China bombs. I kept them for farm trailer use as they still have a lot of tread but they were 7 years old and we do a lot of travel.
I replaced them with D rated tires because they were only $20.00 a tire more.
Weight wise, my loaded for the road 25 ft. TT crosses the scales with 5700 lbs. on the 7000 lb. rated axles and 700 lbs. of tongue weight.
Since my new tires are C rated at 55 psi and D rated at 65 psi. I run them at 60 psi. This gives me a bit of leeway on the tire pressure.
From past experience 65 psi transfers a lot of shock to the TT.
Speaking from experience, a rim bending road hazard will wipe out any tire, regardless of its load rating.
