Enclosed Trailer tires are tires that are used for the specific use of enclosed trailers. Often times people will install a car or truck tire on a trailer, this can lead to many problems. Enclosed trailer tires are generally under more load than normal car and truck tires and therefore are rated differently. Each enclosed trailer tire is rated by a letter rating, known as a load range, that is generally from A-G. This rating corresponds to the number of plys or the thickness of the tire wall. The more weight that will be placed on the tire, the thicker the tire should be. For example a LR-G or load range G is a 14 ply tire that can support a load of 3,750 pounds when inflated to 110 pounds per square inch. The tires on your enclosed trailer will ultimately determine your success in traveling down the road, so do underestimate their importance. Make sure that the tire you are using can handle to load, otherwise a blowout may occur. If you tire experiences a blowout at high speeds, you may lose control of your trailer and tow vehicle. Saving a little money on a cheaper tire will not compensate you overall if you have a serious problem on the road. Consult you trailer sales design team at Millennium Trailers, 1-800-978-7223, to make sure you have the right tires.