Most GM vehicles are now equipped with steel belted all season radial tires as standard equipment. These tires qualify as snow tires, with a 37 percent higher average rating for snow traction than the non-all season tires previously used. Performance in other areas, such as wet traction, rolling resistance, tread life, and air retention is also slightly better. The above changes are the result of improvements in the tread design and the tread compounds. These tires are identified by the symbol M+S. This symbol follows the size and is molded with the size into the tire sidewall. The suffix MS, which follows the TPC specification number, is also molded into the sidewall.