Originally Posted by meterguru
There are differences in the driving requirements between the tires on your trailer and those on the car or light truck you use to tow it. Therefore, there are distinct differences between the way trailer tires and tow vehicle tires are engineered.
Your tow vehicle is a leader, which means traction is a key focus in the design of its tires. Traction allows your tow vehicle to accelerate down the road, turn around the corner and brake to a stop. Another important consideration is tow vehicle tires are designed for ride comfort, which is achieved in part by allowing their sidewalls to flex.
Your trailer is a follower, which often makes tire sidewall flexing a negative. Sidewall flexing on trailers, especially those with a high center of gravity (enclosed/travel trailers) or that carry heavy loads, is a primary cause of trailer sway. Typical passenger radial tires with flexible sidewalls can accentuate trailer sway problems. The stiffer sidewalls and higher operating pressures common with Special Trailer (ST) designated tires help reduce trailer sway.
Trailers will be more stable and pull better on tires designed specifically for trailer use. Since Special Trailer (ST) tires are constructed with heavier duty materials, they are tougher than typical passenger vehicle tires. This is a plus because trailer suspension systems are generally stiffer and less sophisticated than automotive suspension systems.
Some people may have luck using LT tires but your safer staying with trailer tires. And you can't judge tires by outward appearance, I had 4 blowouts in 3 days with tires that looked like new on the outside but when we dismounted them and looked inside you couls see where the steel core was rusted and coming apart. That is the reason for the 5 year rule of thumb and that is from the manufactered date which is stamped on tire not the purchase date. Some dealers may have a tire that has been on the shelf for over a year. So check dates.
I understand that. My trailer tires look good, but I'm changing them anyway, they are (2) at 4 years, and (4) almost at their 4 year mark.
I don't want a blow out on my first trip put with this trailer. Just slightly disappointed the previous owner didn't put new tires on before selling it.