There’s a reason why winter tires aren’t called “snow” tires anymore: They’re designed to work in a variety of conditions, including ice, water and cold dry pavement.
It’s the result of a number of technologies packed into each tire, many of which come together in Goodyear’s new Winter Reactive Technology, or WRT. It was recently introduced on Ultra Ice Grip WRT tires for light trucks, SUVs and crossovers.
WRT includes a new rubber compound, unidirectional tread and two designs of special “blades,” which are micro-grooves in the tire’s tread.
“Everything’s a combination,” says Mike Cosentino, category manager for consumer tires with Goodyear Canada.
“The winter compound is designed to keep pliable in good temperatures, while the blades are constantly moving as the tire’s going around to help with traction.”
Each of the blade designs has a specific function. The two-dimensional blades open as they touch the asphalt, providing more rubber surface to help the tire grip the road during acceleration or braking.
Since the winter-specific rubber compound is relatively soft, three-dimensional blades near the edges of the tire use Goodyear’s proprietary TredLock Technology, locking together to provide more rigid support when turning a corner.
“They’re like Lego blocks that open and close,” Cosentino says. “They’re constantly moving as the tire’s going around to help with traction, and as they close together, they give you more of a robust shoulder, particularly for these heavier vehicles.”
The rubber compound is a new formula developed by Goodyear. It contains polymers, rather than the silica sand that’s commonly used in tire compounds, to improve its grip on cold pavement.
The final piece of the puzzle is a tread pattern design that quickly channels away slush and water. A tire that doesn’t do this has a tendency to “float” on top of water puddles, a potentially dangerous situation known as hydroplaning. Since the tires aren’t in contact with the pavement that’s under the water, the car can skid out of the driver’s control.
Goodyear plans on extending the WRT technology to passenger car tires next year.
By itself, rubber tends to get hard in cold weather and soft in hot weather. That’s the opposite of what you want in a tire, so rubber is blended with other ingredients into compounds appropriate for these temperatures.
So-called “all-season” tires are a compromise between summer and winter tires. Below just 7C, they lose their grip and are inferior to winter-specific tires, even on dry pavement.