- Mud Flaps
- Engine Tuning
January 28, 2010
For over 15 years, many drivers have chosen Bridgestone Blizzak tires to handle the worst driving conditions winter can throw at them — slushy, snow-packed or ice-covered roads. And with that, Blizzak tires have become synonymous with wintertime mobility and driver confidence.
But technology doesn't stand still. In an effort to keep improving winter snow and ice traction, Bridgestone developed the new Blizzak WS70 Studless Ice & Snow winter tire, designed for passenger cars, minivans and crossover vehicles. Because the Blizzak WS70 was previewed to tire dealers and members of the media before it was available to the public, select members of the Tire Rack team travelled to Steamboat Springs, Colorado in January 2010 to experience the snow and ice traction of the new Blizzak WS70.
On the Ice
Our day started at the local skating rink, which provided a good simulation of the glare ice conditions often found at slippery intersections in wintertime. The first demonstration was to accelerate from a standstill to 10mph before reaching the center ice line. Two identical 2010 Toyota V6 Camrys were equipped with Bridgestone Blizzak WS70 and Michelin X-Ice Xi2 tires. The Camry's traction control system was left on to assist the driver in managing any wheel spin that might occur. Both sets of tires were broken-in prior to testing by driving on clear roads for approximately 6,200 miles/10,000 kilometers.
First up was the Michelin X-Ice Xi2. From a standstill, this tire required careful throttle application to avoid immediately engaging the vehicle's traction control. Care was needed as the run to 10mph progressed to avoid additional wheel spin. Next was the vehicle equipped with Blizzak WS70 tires. This combination eased away from the starting line with no noticeable wheel spin, and felt as if the car could accelerate harder than the one equipped with X-Ice Xi2 tires. So much so that it was somewhat easy to quickly overshoot the 10mph speed target due to the additional acceleration capability.
Once leveled off at 10mph, a quick, fast application of the brakes was done at the center ice line to bring the car to a stop using the vehicle's Antilock Brake System (ABS). A Vericom VC2000 performance computer was used to capture the vehicle speed and distance required to stop. The vehicle fitted with Blizzak WS70 tires was able to stop approximately two feet shorter on average than the car equipped with the X-Ice Xi2 tires.
As a final visual demo, one of the cars was fitted with a mix of both tires — Blizzak WS70 on one side (front and rear), and X-Ice Xi2 on the other. ABS was deactivated, so all four tires would lock upon hard application of the brakes. The theory being that the tire with more absolute grip will slow its side of the car faster, inducing a yaw motion towards the higher grip tire. Accelerating to the center ice line, the driver gave a sudden application of the brakes to lock the tires. As anticipated (based on the acceleration and braking demos) the Camry yawed to the left, toward the side where the Blizzak WS70s were installed.
In the Snow
After our drive on the ice, we headed over to the Bridgestone Winter Driving School. Here we found two more 2010 Toyota V6 Camrys fitted with new Bridgestone Blizzak WS70 and Michelin X-Ice Xi2 tires (both sets were given 100 miles of clear road driving prior to testing).
The Winter Driving School track features gently rolling terrain covered in an ice base with a mix of packed and loose snow on top. By the time our team took to the track some corners were already swept clean from earlier driving, exposing the icy base layer. ABS and Traction Control were left on to help the drivers maximize the traction of both tires.
The Blizzak WS70 displayed very good snow acceleration as the car entered the course and got up to speed. Cornering traction was similar, with the tires providing good front-end authority to maintain directional control. Braking felt sure-footed, too, with minimal ABS engagement. Changes in cornering traction were modest as the car encountered patches of exposed ice. The Blizzak WS70 displayed good residual grip once the limit was reached, continuing to provide some control on the snow-covered and icy track surface.
The X-Ice Xi2 also displayed good subjective snow and ice traction levels. But when a slide did occur while cornering, there was a greater tendency to get some initial understeer followed by oversteer, particularly when the car crossed icy patches in some of the corners. The X-Ice Xi2 couldn't quite match the poise of the Blizzak WS70 on the variety of winter conditions encountered on the track.