Yokohama Ice Guard reporting for duty. Click image to enlarge
Article and photo by Michael Clark
When it comes to effective snow tires, there’s no better endorsement than winter motorsports.
“It’s the one that all the ice racers use,” said Vern Barker, Store Manager at the Kal Tire dealer on Pembina Highway in Winnipeg. Kal Tire is an authorized Yokohama dealer, with Barker’s location handling the install of Ice Guard IG 721’s on my 2007 Mazda MX-5 GT tester, supplied by the good folks at Mazda Canada. Size availability required the Ice Guard’s to be mounted on (ugh!) fashionable 16-inch black steel rims. Aesthetics aside, a set of steel rims makes perfect sense for your winter skins. There’s no costly changeover fees, and your precious alloy rims won’t be subject to corrosive road salt. The steels are also a little more forgiving when it comes to harsh road surfaces, and a curb thump repair won’t break the bank for wheel straightening.
A quick peek at the tread design reveals that the Ice Guard is anything but subtle when it comes to its ultimate purpose. The outer portions of the tread face consist of two rows of squared-off tread blocks, with a slight zig-zag channel that seems destined to excel at cornering grip. The interior of the footprint uses N-shaped tread blocks, arranged in a unidirectional pattern. This helps to disperse water out from under the tire. The sensation of ‘slipping’ on icy surfaces actually has more to do with hydroplaning, especially when warmer temperatures and road salt promote melting. In addition to the N-blocks, the Ice Guards have six main grooves to aid in water dispersal. The blocks are populated by multiple zig-zag sipes for extra bite.
Compounding all of this is, well, the compound. Aiding the Mazda Zoom-Zoom is Zeruma, Yokohama’s special processing agent. The problem with adding silica to a tire compound is that the silica tends to congregate in pockets, as opposed to even distribution throughout the rubber. The Zeruma process solves this problem, which makes the tread blocks more flexible when colder temperatures arrive. The more flexible the tread block, the more road surface that it can come into contact with. Translation: traction.
As the tire wears, shelled micro bubbles add to the grip. As the bubbles start to open, the voids they create on the tread surface help to break through the thin film of water on ice. This means direct contact with the tire and the surface below.
Once again, the 2-week test period dealt with some wide temperature variances, with a high of near freezing and a low of minus 20 degrees Celsius. The biggest problem was an unexpected lack of precipitation. Luckily, back lanes and side streets had yet to receive a needed scrape. The consistency of the snow behind Casa Clark was quite deep, possibly due to my shovel boycott. My laziness paid off; the snow and road salt mixture was practically sand-like in texture. The Ice Guards dug like rabid moles into the flakes. Most important was their effectiveness in first gear. Minimal wheelspin was observed under these conditions. Even with numerous jagged sipes, the Yokies did not elevate interior noise levels, even at highway speeds.
The sun continued to beat down, reducing many side streets to slippery slick. Even at speeds approaching Not A Good Idea, the Ice Guards would still provide impressive stopping grip, without engaging the ABS. Even without studs, or added trunk weight, The Eye-Gee’s were a delight in low-speed corner navigation, with just the slightest hint of oversteer. The oversteer was surprisingly light, even when the throttle was pushed beyond reasonable limits. The technology definitely paid off as the MX-5 tracked through corners, with understeer occurring only at the edge of stupidity. At $178.00 per tire, the 206/50R16 Ice Guards are a bargain that requires little thought process.
For those of you concerned with my well-being, (Hi Mom.) I am pleased to report that climate control within the MX-5’s cabin has been most livable. The heater system is first rate, with quick warm-up and proper upper and lower delivery. A glass rear window means an effective electric defrost. The leather seats are heated, though there are only two settings; off and very hot. Mazda would be wise to consider a two-step heat setting at minimum, with the ultimate solution being a roll-dial arrangement. It takes a little while to find the right temperature placement, and this will vary depending on how much wind is pummelling the soft-top. To their credit, the MX-5’s softie is both air and automatic car wash-tight. Not even a dribble of multi-coloured suds makes its way through a weatherstrip. With the Intelligent Key System, lock de-icer is a thing of the past. Even with forgetful chamois wipes at the car wash, the MX-5 has yet to disallow entry on frigid mornings.
On deck for the MX-5 will be the first test of studable tires; a set of Cooper Weather-Master S/T 2’s. This will be a two-pronged evaluation, with one week with studs, and one without.