We had Goodyear Wrangler LT tires on our Fifth Wheel. Within a year they all failed. Used Armor All, a no no. Could see tons of checks in them.
On our F150 Lt tires but Michelin,we have new ones since Jan. The last st had over 00,000 miles and four or five years and no problems. Tires not degraded at all.
I perceive that from statements by tire people and here and my own observations that most towables tires from the factory are on the edge of load range and such.
They incur more heat and stress then they should and along with uv they break down easier.
ST tires are all designated for lower speeds I understand but don't know.
They cost more but have more uv protection.Lower speeds liek 40mph is impractical. One up on size and load range and heavier duty aluminum wheels might solve most of the tire problems with towables.