M+S tire designation meaning September 05, 2009, 03:32:14 pm Yahoo Message Number: 105557I sent this link from the "How Stuff Works" website to a person who asked me about the meaning of the M+S designation on a tire; I thought some people on this forum might also be interested in the tread pattern that qualifies a tire to receive a M/S designation from the Rubber Manufacturers' Association: http://auto.howstuffworks.com/tire3.htmTwo comments on the tread pattern of a designated M+S tire: The M+S tire is *not* necessarily designed for "severe winter use"; tires that are appropriate for severe winter use (something that I avoid!) have additional requirements, and are designated by a special insignia (shown on the page). How "rock grabby" a M+S tire is depends on a particular tire's tread pattern, but the M+S tires' wider-spaced tread grooves usually pick up (and hold) more little rocks and gravel than tires designated "highway" or "all-terrain" tires.HTH,Joan