January 28, 2010
Tires Tested
Bridgestone Blizzak WS70
(Studless Ice & Snow, 215/55R17 94T)
Michelin X-Ice Xi2
(Studless Ice & Snow, 215/55R17 94T)
Vehicles Used
2010 Toyota V6 Camry
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.