Originally Posted By: dailydriver
Originally Posted By: dparm
What's nice about these is that the ice traction does not wear out or stop halfway through the tire's life like the X-Ice or WS70.
I knew all of the B-Stone winters turned into all seasons at half tread life, but I never knew the Michelins did as well.
I don't believe any actually have any all-season compounds, but rather different types of winter compounds. Blizzaks with the Multicell compound supposedly have this for maybe 55% of the tread depth, which then uncovers a standard winter rubber compound.
Quote:
http://www.tirerack.com/winter/tech/techpage.jsp?techid=116
The Blizzak WS-tires’ Multicell tread compound comprises the top 55 percent of the tires' tread depth with a standard winter tread compound comprising the remaining 45 percent. When Blizzaks are approximately 50 percent worn, their "snow platform" tread depth indicators "connect" selected shoulder tread blocks to indicate that the Multicell tread compound is almost worn out, and that the enhanced snow and ice performance is about to end.
In California, once you're down to less than 6/32" tread depth, a tire doesn't qualify at all as a "snow tread tire" that can bypass either R1 or R2 chain conditions without chains. They don't care as long as it's stamped M+S somewhere and there's a deep enough groove. I've been checked several times in my WRX. I understand it can be anyone from a Caltrans or county worker, as well as law enforcement. Once I went through a chain check at Yosemite, where it was a law enforcement park ranger.
It's usually "OK, Subaru" with a look (including a flashlight at night) at my left front tire. I've never had more than a quick glance, but my tires have never been anywhere near the minimum when I've taken it in the snow.
I think with the requirement for minimum snow tread in several states, the tire makers have an incentive to indicate that you need new winter tires, but only by marginally reducing their usefulness for winter conditions.