The use of nitrogen Truth?
With the addition of 100% nitrogen (impossible!) you will loose 30% less air in the tire over a years period than if inflated with atmosperic air.
Which if you figure the cost of filling your tire with nitrogen to begin with is pretty much a wash! Nitrogen doesn't keep your tires cooler, last longer nor does it handle better or stop quicker!
The molecules of Nitrogen are bigger than Oxygen Molecules and don't escape thru the rubber as quickly as oxygen does.
Before trying LT tires (LT stands for Light Truck), remember that ST Tires are built and designed for Light trailers...if you've ever watch a TT while it's backing up and turning at the same time, the tires are subjected to huge twisting and deformation forces. But not to worry! ST Tires are made to hold up under these stresses. LT tires may cause your triler's ride to become harsh.
Per the tire experts at The Tire Rack, "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 car 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.
Special Trailer (ST), as well as Light Truck (LT) tires are fully rated for trailer applications. This means ST- and LT-sized tires can carry the full weight rating branded on the sidewalls when used on a trailer."
I scored a set of 4 Goodyear Marathons made in New Zealand last tire change. I've always ran with USA or Canadian made Marathons because the 7 Jayco's I've had came with Marathons. I'll probably go with Maxxis next time if I can't find non-Chinese Goodyears.