I had similar problems and found there are additional specs to look out for. Many trailer tires are rated for high pressure and low speeds. States like Arizona have legal towing speeds of 70+ mph. Now that doesn’t mean you have to go that fast, but the tires are rated to handle it.<blockquote>
Service Description
The service description of a tire includes its load index and speed ratings. These two ratings tell us how much
weight the tire can support and the maximum service speed of a tire.
Load Index
The load index of a tire is a number that corresponds to the maximum load in pounds that a tire can support when properly inflated. The maximum load in pounds and kilograms will also be molded on the tire sidewall.
Speed Rating*
Many Goodyear tires are available in speed-rated versions to match the speed capabilities of the world’s fastest cars. Generally, it is recommended that a speed-rated tire be replaced with a tire having an equivalent or greater speed rating.
However, if you never drive at speeds near the limits of your speed rated tires, you may choose to replace them with tires having a lesser top speed rating.
In situations where tires having different top speed ratings are mixed on a vehicle, the maximum speed certification is limited to the top speed certification of the tire with the lowest speed rating.
Speed ratings do not indicate how well a tire handles or corners. They certify the tire’s ability to withstand high speed.</blockquote>I decided to go with Good Year
Light Duty Truck Tires with a higher speed rating. They don’t
fall apart at highway speeds and are designed to carry the
weight at lower tire pressures giving a smoother ride in the trailer.
You might start looking at
http://www.goodyeartires.com/goodyeartires...=98&image.y=28#