The trailer industry, which includes utility, boat, TTs, 5vers, horse, cargo and assorted other trailers wanted a tire for use on their products.
They needed a tire that would have 1,a stiff side wall that would handle the side loads of parking and other such maneuvers, 2, a tire that had low rolling resistance, 3, a tire tread designed for pulling not transferring torque to the payment, 4, rubber compounds that were resistant to sunshine and ozone 5, cost less than a conventional tire.
The tire industry responded with the ST tire. To use ST tires the trailer industry had to give up 1, the more robust designs and material used in the LT light truck tires 2, limit the speed to 65 mph, 3, using ST for any turning or traction related application.
To assure proper usage some ST tire are stamped "for trailer use only". Also, though most LT manufactures will agree that their LTs tires can be used for TT service, they are not advertised or recommended for such used.
In recent years the tire industry has seen the need for higher speeds and more durability across the trailer market, so the tire makers have developed new tires to fill this need. However given the increased cost of these newer products, there are not likely to replace the one million plus standard ST tires that leave the various TT and other trailer markets every year.
The vast majority of trailer users are satisfied with their ST trailer tires but those who are not, the new crop of faster, stronger, and more expensive tires are available.
