Firestone
Firestone is the U.S. subsidiary of Japanese manufacturer Bridgestone. In addition to its winter tires for passenger vehicles, Firestone also produces the Winterforce LT , a tire specifically designed for heavy-duty trucks (the sidewall stiffness comment mentioned above about Goodyear applies here as well). In addition to its aggressive tread, this tire is distinguished by its ability to be studded before it is put on.
Photo: Firestone
Winterforce LT, by Firestone