After giving Green Diamonds a try in the 2007 season, the unstudded rubber-on-ice crowd has reverted back to the old favorite, the Bridgestone Blizzak. What sets these apart from traditional snow tires and puts them in their own category of performance is tire compound. Bridgestone uses a compound that is very soft and remains pliable at cold temperatures. This combined with aggressive “siping” (jagged tread cuts) gives them a superior coefficient of friction when they can find asphalt through the snow at below-zero temperatures, and makes them a predictable winner in outright winter performance. The disadvantage to this is that soft, floppy tread wears much faster and gives poor dry-road performance. This is a totally worthwhile trade-off in my opinion, as “performance” snow tires that trade snow and ice traction for asphalt traction are not very good (a word on that later). Interestingly enough, Bridgestone now uses “bite particles” in the compound, which sounds an awful lot like Green Diamond’s strategy. I haven’t seen shiny slivers sticking out of these tires, so perhaps these particles are rubber-colored.

WS-50 vs. WS-60:

The AMEC “street legal” ice racing class started off with Blizzak WS-50 tires when they were new. Last year, the new Blizzak WS-60 replaced the aging WS-50 and racers were split between the last sets of WS-50s that were available and the newly stocked WS-60. By the end of the season, the general consensus seemed to be that the WS-60 offered better traction. Clint ran a set for the whole season and found them to have excellent performance on ice and snow. I drove a 3 hour endurance race in Maine on WS-50s and against a field of cars with studded tires. As the ice conditions improved and the course became more textured, I discovered I could beat some of them through the corner at the end of the main straight. Yes, braking from 70mph on ice to pitch the car through a 20mph corner was as good with unstudded Blizzaks as metal studs digging into the ice.

Having used Blizzak and several other winter tires in the past, I wanted to sample Green Diamond’s technology to see if it gave an edge on ice without using studs. After this experiment, I find that the grass was not greener after all, and that Blizzaks are still the best out there. Bridgestone is so confident about their performance that they sponsor AMEC ice racing (and no, that doesn’t mean we get cheap tires). I share their confidence in recommending Blizzaks as the best snow and ice tires I have ever used.

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