“Why don’t all chocolate cakes taste the same? Answer: the ingredients — and how they are mixed. So, too, for the best winter tires,” says Woody Rogers, product information specialist at Tire Rack.
“At the primary level, tires need three things: 1.) sufficient tread depth; 2.) an appropriate tread pattern; and 3.) the right tread compound.”
Tire technology has changed radically over the last 20 years. Tire buyers today confront a variety of options including footprint, compounds, bite particles, tread patterns and more.
Years ago winter tires were called “snow tires,” and you only used two of them in the back because most cars were rear-wheel-drive, notes Chris Welty, education specialist at Bridgestone.
Rogers of Tire Rack also explains, “Winter tires rely on tread depth to take real bites of snow and slush, rather than just nibble at it. Today’s winter tires feature a supplemental wear bar, called the winter wear indicator or snow platform. The snow platform tells the driver when the tire has worn down enough that it can no longer perform well as a winter tire.”
He also adds, “Sipes (thin slits molded into tread blocks), provide additional biting edges. Each sharp edge digs into the snow or presses on the ice surface, aiding traction,” says Rogers. “Sipes are enhanced further by creating a zigzag or S-shaped pattern along its length. Sipes are furthered by creating a 3-dimensional zigzag, side to side and top to bottom.”
Rogers makes the comparison, “If you’ve ever had a waffle stick to the iron, you can imagine the challenge of manufacturing a tire with thousands of zigzag sipes.”
Bridgestone Blizzak’s traction uses a multi-cell compound composed of microscopic pores that look and act like a kitchen sponge. These tiny pores give the thin film of water that forms under the tire a place to go, improving rubber to road contact and traction. In simple terms, it’s much the same as moisture-wicking athletic clothing that helps move perspiration away from your skin.
“The tire can change your car more than any other item,” according to Bridgestone’s Welty. “In a winter tire like the Blizzak, the tread design is designed to pack snow into the tread. Think about it as if you were building a snowman — you build it up by rolling snow onto the snow. If you can pack snow into the grooves of the tire, the snow on the ground will stick to the snow on the tires.”
I also attended the Winter Media Drive for Chrysler, Dodge, Ram and Jeep at a closed track in Quebec. These vehicles featured all-wheel-drive and four-wheel-drive equipment.
Fiat Chrysler Automotive has kept the zest in its AWD cars like the Dodge Charger and Chrysler 300. I drove the 2015 Charger Pursuit Police car with AWD, which delivers 0-to-60 mph in less than 6 seconds.
The Dodge Charger AWD and Chrysler 300 AWD feel sure-footed and spunky on the track; off-road vehicles like the Jeep Cherokee and Renegade “kicked snow and dirt” and don’t skip a beat. And the Ram truck just dances its way through the cones.
Welty of Bridgestone concludes, “It takes five-plus years to engineer a new tire. Every year we spend $1 billion for research and development. We work on new tread patterns, internal elements inside the tires, fuel mileage, eco technology and more. However, this technology isn’t just for one type of tire. One discovery tends to work well in 80 percent of the tires, so techniques are shared.”
Rogers says the most advanced winter tires are: Bridgestone Blizzak WS80, DM-V2 (3-D Sipes); Michelin X-Ice Xi3; Latitude X-Ice Xi2 (Cross Z-Sipes); and Yokohama iceGUARD iG52c (Triple 3-D Sipes).
— Holly Reich, Motor Matters
Copyright, Motor Matters, 2015
Manufacturer Photo: Holly Reich in Quebec at the Fiat Chrysler Automotive winter driving track.