When you see the M+S symbol on a tire, this means that you’ll be able to use it for muddy and snowy environments. This is a sign that it’s an all-terrain tire. Some will also have the snow-covered mountain symbol to show that they’re all-terrain tires that is made for snowy weather, too. Don’t just trust the symbols, though. Take a look at the sipes and ribs to check whether they are wide enough to reject the snow while also having enough strength to penetrate through it, as well.