Big deal. A tire is a tire, right ? Wrong. As a matter of fact there's a big difference between trailer tires and your own car tires. First of all the side walls in any passenger vehicle tire are made to flex. A vehicle's tires are designed for ride comfort. Your trailer is made to haul loads and follow behind. Sidewall flexing on trailer tires is not good at all, especially those with a high center of gravity like an enclosed travel trailer. it's the primary cause of trailer sway.