Trailer tires are designed for stability. They are 6 ply bias treads and run inflated to 50-60 psi. All this to minimize sway caused from side wall flexing. Not all normal tire stores carry these, you will need to shop around. Don't be tempted to use normal car tires, unless you never want to drive at highway speeds, the risk is too high. I have Cobra trailer with a DG 800b pulled by a Range Rover sport with low profile tires and can drive all day at 75mph with no problems at all with sway. I use to pull the same trailer with a 4 Runner with high profile radial tires, nearly have multiple accidents with sway problems, I was lucky.

Buzz Graves