 The winter beast for The Roadtrip, courtesy of Mazda Canada. Click image to enlarge |
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Winnipeg, Manitoba – Winter tire testing may also be known as the Great White Confusion. Confused? Let’s consider the bulk of snow tire reviews. The tire specs, the vehicle fitment, the experience on road or track; the general admission that all snow tires perform better on snow and ice than the all-season solution. For the most part, Canadians get it. During a recent radio interview on The Roadtrip in Winnipeg, Motoring TV’s master mechanic Bill Gardiner made reference to the abundance of snow tire use he has personally witnessed in Eastern Canada. The black steel rim with the winter skin is most definitely ‘in’.
However, what Winnipeg and the rest of the country don’t seem to get is that traction control and anti-lock brakes do not result in summer driving conditions in the middle of January, even with winter tires. One only needs to keep an eye on the claim centres for Manitoba Public Insurance to prove this point. Vehicles headed to the salvage yards tend to be suffering from low-speed impacts to front and rear bumpers. When the temperatures are in the crispy minus Twenties, those plastic bumpers shatter like glass. Outside the city, the ditches continue to fill with commuter vehicles, many having four or all-wheel drive. The culprit is speed, and the misconception that traction achieved upon acceleration will always remain as sticky road grip.
 The dreaded Sadler and St. George. Spooky. Click image to enlarge |
For this test, we’re going to let pylons be by-gones, and search for the most slippery of side street intersections in the South part of the city. (Note: testing was performed with no competing traffic present.) At press time, that animal was the four-way stop at Sadler Avenue and St George Road, in the St. Vital district. The shoes were Continental ContiCrossContact Winters, easily identified by their over sized snowflake patterns on the sidewalls. (Go to Conti-Online.com to view the handling characteristics animation for these tires.)
As with any winter tire, Conti speaks of its proprietary silica-rich, polymer-laced tire compounds, which contribute to the most important factor for any tire touting its winter prowess; elasticity. (If it can’t flex, it can’t stick.) Flexibility can be a cruel mistress. If the tread block flexes into the other block under load, the traction that could be achieved by the block edge is lost. The shape of the inner-most tread blocks on the Conti’s addresses this concern, allowing the blocks to flex and lock into each other, while still providing enough of a block edge to assist with cornering bite. The tread blocks use multi-edge sipes, which resist interlocking. The longer the sipe stays open, the more snow it can swallow, exposing the traction edge of the sipe sooner to the road surface. (Think of the sipe as a baby tread block edge.)
Sturgeon Tire of Winnipeg took care of the mounting duties for the 2010 Mazda CX-7 tester, itself a unique piece. Instead of opting for the turbo all-wheel-drive, The Roadtrip opted for the new front-driver, powered by a normally-aspirated 161-horsepower 2.5-litre inline four. The point? To prove it’s the tires that matter, not the amount of differentials you possess. An all-wheel-drive unit would certainly have a leg-up on take-off, though our concerns for this test deal more with the issues of braking, and recovery, from purposeful engagements of the traction control system.
Speaking of systems, the tire pressure monitoring system provided the expected low pressure warning, due to the required use of the Conti’s in 225/65R17 sizing. The stock fitment of 215/70R17 is a bit of an oddball, though variations in tire size for winter use are not uncommon. Your local tire expert can ensure that the winter tire size does not cause any clearance issues, or throw the speedometer out of whack. Tampering with a tire pressure monitoring system is frowned on by most manufacturers warranties, so learn to live with the instrument panel warning. (And carry a tire gauge.)
 The Continental ContiCrossContact Winter. Now with bigger snowflakes.. Click image to enlarge |
The corner of Sadler and St. George in Sunny St. Vital may not have the appearance of a notorious intersection. Truth be told, it isn’t even on the radar for the top five crack-up centres in the city. Nevertheless, these simple suburban crossings tend to get the most amount of polishing for ice, and the least amount of sanding. The goal for the braking test was to determine the maximum speeds where braking could occur with the Conti’s, without engaging the ABS. Like any intersection, these passes would occur on the tracks with the most amount of ice, and the off-centre tracks of sand and grit, where the seasoned winter drivers tend to wander.
Approach speed to the intersection was kept at about 35 km/h, slowing first to a speed of 30 km/h within a reasonable stopping distance, best described as where any reasonable Canadian would start to apply braking pressure. On the icy tracks, ABS kicked in almost immediately, as it also did at 25 and 20 km/h. Remember to keep your foot firmly planted on the pedal, and the Mazda stops in time. Lowering the approach speed to 15 km/h was the key to minimal ABS intrusion. Don’t forget; this is on sheer ice. Move the Mazda off of the ice tracks to the grit, and the story changes considerably. With 10 passes in the grippier tracks, the Mazda could be finessed to a stop at a maximum 25 km/h approach speed, with no ABS mitigation (your Sadler and St. George may vary.)
Now wait a minute, you’re probably asking yourself. Shouldn’t there have been no ABS mitigation with the wonder that is silica/polymer compound and sipes-a-plenty? Hardly. Winter tires stop better on snow and ice than an all-season skin, The End. They do not re-create summer driving conditions. To prove the point, The Roadtrip added another simple test; cross the intersection by foot, carefully. If you’re fighting the urge of Nature to send your hiney over tea kettle, so are your tires. A little bit of ABS input can be both a gentle caution, and simply required.
Testing the Dynamic Stability Control system was a little more involved, and is just plain not recommended for the novice. Using a low-traffic dead-end service road, the CX-7 was brought up to a speed of 45 km/h. To engage the DCS, the steering wheel was cranked through a series of rapid half turns to the left and right. This is where the inner tread block pattern of the Conti’s really shines. With all-seasons, this manoeuvre can get dicey in a hurry. The braking inputs from the DCS were not overly harsh, even comfortably predictable. The exclusion of a DCS alarm chime was most appreciated.
Traction control systems can sometimes feel like the Throttle Pedal of the Living Dead. The CX-7 system allows one to press down with considerable force, working more as a limiter than an outright throttle cut. What you get is best termed as sensible wheelspin, on a straight line of travel.
The question for many in harsh winter climates is the benefits of studded tires. The Roadtrip’s tester was first fitted with the Gislaved Nord*Frost 5, equipped with an irregular pattern of studs. These will be the last set of studded tires used on the tester for the winter months, as the search continues for compounds, tread blocks, and proprietary technologies that can rival the performance of a studded tire on ice. In the case of Sadler and St. George, the Gislaveds still encountered ABS input during braking, albeit far less than the non-studded Conti’s. Why? The roadbed ice is currently about two to three inches above the road base. Experience has proven that studded tires work best on thin layers of ice, where contact with the roadbed is imminent. Then there’s the noise factor. You will never forget that you have studded tires, with a constant low hum from beneath on hard road surfaces. If you live in an area of ice and corners, (Lucky Dog) go studded. And turn up the radio.
A factor that seems to be in contradiction to winter tire performance is the issue of aqua, or hydroplaning. If you’ve ever experienced this phenomenon in the summer months, it most likely occurred during a torrential downpour, at a higher rate of speed, and with knuckle colour set on Bright White. Aquaplaning happens in the winter too, though with far less water, and far less speed. A thin film of water between the tire and an icy road surface is all that it takes to start slipping. Continental and Gislaved speak volumes about their water evacuation abilities. Get rid of the water, get back the grip.
Canadian winters are anything but simple to predict, so it is important to assess your daily driving needs when choosing the tire that is right for you. One should also remember that winter tires will not always mimic a summer tire’s performance. For the arena of Sadler and St. George, The Roadtrip recommendation steers towards aggressive tread patterns, which may not always be the quietest, but offer the highest abundance of traction-grabbing block edges. Lastly, slow waaaaaay down.
