Being headquartered in Michigan, where winters are usually grey, very often snowy, and bitterly cold, we’re major proponents of winter tires. Indeed, if you’ve ever driven a car on winter tires and experience the kind of additional stopping power they provide when ice, snow, and slush cover the roadways, you no doubt feel the same way. Of course, driving or testing winter tires in appropriate conditions is difficult in all but the coldest portions of the year, which is why Hankook invited us to Ivalo, Finland, some 186 miles north of the Arctic Circle, where we sampled its winter tires at an indoor facility called Test World.
-Test World sits just a short distance east of the 4000-person city of Ivalo in the Lapland region. Lapland is about the size of Indiana, with the total population of Worcester, Massachusetts, but the only thing Lapland and “Wooster” have in common is funky pronunciations to us Midwesterners. Given that there are few signs in English, you need GPS to navigate—without it, you’ll likely end up in Russia, Norway, or Sweden.
-You might think that indoor winter testing is commonplace. Tire Rack does a lot of testing on ice rinks as well as outdoor venues, but Test World is different than most manmade winter facilities in that the staff stockpiles natural snow in early spring and fills its two buildings with about 60 cm (24 inches) of packed white stuff. It’s worth noting that you can’t just dump a ton of snow in at once. Five-millimeter (0.2-inch) layers are applied and then given time to settle to make the resulting packed testing surface as natural as possible. Carefully controlled humidity and temperature keep snow loss, or evaporation, to a minimum. The painstaking process ensures consistent testing conditions, which is critical to tire development.
-Hankook showed us its worldwide catalog of winter offerings including a newly updated Winter i*cept Evo2, a performance winter tire available in the U.S. For those less familiar with winter tires, they can be grouped into roughly three categories. (There are more, but these three cover all the basics.) First are the studded winter tires that are fairly self-explanatory; metal studs inserted in the tread provide maximum grip on ice. Then there are studless snow-and-ice tires, which are our favorites because you get the most traction possible without noisy studs humming in your ear (not to mention studded tires are illegal in many places). Then, there are the aforementioned performance winter tires. These tires are generally rated for higher speeds—the Evo2, for example, is rated for 168 mph in some sizes—they come in lower-profile sizes, and they are usually constructed with an asymmetrical tread pattern. Performance winters give up traction on packed snow and ice in favor of improved performance in mixed conditions, or in the cold, wet, slushy mess that is common in metropolitan areas.
-Our day of Hankook evaluation started with braking and accelerating on ice and on snow, getting a feel for what Test World does on a day-to-day basis. The interior thermometer reads about 12 degrees Fahrenheit, so it’s 20 degrees below freezing despite being nearly 60 degrees outside on the day of our visit.
-Indoor acceleration and braking tests are methodical in the 525-by-52-foot Indoor 1 building. First, accelerate to 18 mph on the snow, then slam on the brakes. Data is collected with optical fifth wheels because the roof eliminates the possibility of using GPS data loggers. Testing on the single lane of ice requires surface preparation, which is just making multiple passes, carefully putting the tires on the same path each lap to even out the surface.
-On snow, every run is done in fresh tracks. Once all the available space is used up, Test World resurfaces the snowpack with a Toyota truck that does a great impression of an MLB grounds crew dragging the dirt. Scraping the top layer of snow keeps the surface as natural as possible.
-Next came the real fun in what Test World calls Indoor 2. This is an indoor handling circuit nearly 1200 feet long and 30 feet wide (not counting the snow drifts). From a bird’s-eye view, it looks like someone drew the outline of a giant Jelly Belly and built a squiggly barn over it.
-Driving up to 40 mph indoors on packed snow with no runoff room feels like doing 150 mpg on an open racetrack. There is no room for error, and even worse, as laps accumulate, grip starts to drop in places where the packed snow has been tossed around by tire spin and ABS-assisted braking. Under normal circumstances, the Test World team resurfaces Indoor 2 after every test tire has done a full test loop, which is about eight laps.
-As on Indoor 1, GPS isn’t an option for data collection. Indoor 2 is mostly a subjective evaluation where testers concentrate on tire feel more than objective results with a lap timer keeping tabs on consistency, which is more important than outright speed when testing tires. Indoor 2 is where you get a sense of how the tire feels while braking into and powering out of a corner.
-Test World’s indoor facilities don’t replace its own hundreds of miles of outdoor track, but they do successfully supplement development and stretch the testing season from just a handful of months per year to year-round.
--
- -
- Winter-Tire Test 2015: Six Top Brands Tested, Compared
- -
- How Winter Tires Work, Presented as a Pleasing Graphic
- -
- Winter Driving Guide: Tips to Survive the Snow and Ice
- -
-
In the afternoon, we drove the Evo2 on dry roads to the Russian border and back. The terrain isn’t all that different from Michigan’s Upper Peninsula and the border looked only slightly more guarded than the Mackinac Bridge toll booth. The Evo2’s asymmetric pattern kept tire noise to a minimum and it tracked quite well on the Finnish roads. Without having driven it on snow or ice, we can’t say for certain how it might stack up in a full winter-tire test like the one we just published (and which was conducted at Test World), but we’re going to attempt to fit a set to one of our long-term cars this winter and will report back.
-from Car and Driver Blog http://ift.tt/1MQT3JK
via IFTTT