The load and speed ratings of the ST225/75R15 trailer tires your 2017 Dutchman Aspen travel trailer are maximum capacities for the tires themselves. The 75-mph maximum speed of an L-rated tire does not indicate a recommendation to tow a trailer at that speed.
Safe towing speeds naturally vary based on the nature of the road (dead-straight flat interstate versus winding two-lane back roads), the weather conditions and the total weight of the truck and trailer as a combined system. Also,... view full answer...