SNOW TIRES: THE COLD FACTS
Purpose-built winter tires are the only ones to use if driver safety is your #1 priority
By Bruce W. Smith
Winter can bring with it a variety of adverse weather conditions from snow and ice to rain and fog. All of these unpredictable elements can make driving in winter challenging for everyone.
According to recent studies by Goodyear Tire, more than 75 percent of surveyed drivers believe winter tires make a difference in challenging winter weather, yet 58 percent of those in cold-weather areas don’t use winter tires.
That’s not really surprising, as the typical consumer doesn’t want to pay for the cost of having two sets of tires: one for winter, the second for the other eight months of the year.
But the ones who face the worst winter driving conditions day in and day out – and who should make that seasonal tire change – are contractors in the Midwest and northern tier states whose living depends on their pickups performing and their drivers being safe.
Mark Cox, Director of the Bridgestone Winter Driving School in Steamboat Springs, Colo., says “One of the most important factors in starting, steering or stopping on ice and snow is a vehicle’s tires.”
“It makes no difference if you have a front-wheel, four-wheel or rear-wheel drive, your vehicle will perform better in winter driving conditions if it is equipped with purpose-built winter tires instead of all-season radials,” says Cox, one of the leading winter driving experts in the country.
That’s because “all-terrain,” “all-terrain,” and “traction tires” are designed to perform year-round in most conditions except when the temperatures drop below freezing, and snow/ice becomes the primary driving surface.
It’s then the softer rubber compounds and unique tread design of dedicated snow tires (those with the mountain peak/snow flake symbol) set themselves apart from other tires.
“Tire manufacturers have come a long way in improving winter traction of their all-season tires,” says Cox. “ But a dedicated winter tire is designed specifically to handle winter driving needs.”
The key performance factor of purpose-built snow tires, studded or studless, is the softer and more pliable rubber compound in the tread face – and the tread design itself.
Think work boots: When you are walking in the snow, which boots give a better grip, those with more flexible soles with snow treads or the everyday work boot?
A couple years ago I experienced first-hand the difference between dedicated snow/ice tires and the standard pickup tires while driving a GMC Duramax 2500 Crew Cab 4×4 during a two-day comparison test at Cox’s winter driving school.
The difference in vehicle control between the typical all-season tire and four different purpose-built snow tires was eye-opening to say the least.
One of the reasons for the huge difference in grip between “warm weather” and “snow tires” is tires designed for use in sub-freezing temperatures have a rubber compound that stays very flexible in temps well below zero.
That means the snow tires’ tread bends and twists, remaining in contact with the freezing road surface instead of lifting off as does a typical tire during cornering, acceleration or braking maneuvers.
Then there’s the snow tire’s tread design itself. If you look very closely at a dedicated snow/ice tire’s tread you’ll see every tread block is riddled with little slits, grooves and pores.
These tiny changes in the surface create thousands of biting edges that grip the ice and allow snow to pack in so it grips with new snow that rolls under the tread. (Snow grips with snow.)
In addition to the biting action, the minute cuts, slits and pores absorb the film of water that develops on top of icy roads, thereby allowing the biting edges to adhere to the surface with less interference.
The result is greater steering and braking control on slippery road surfaces than you’d get with other tires.
As James Thompson, a contractor in New York’s Adirondack region, said after switching over his pickups to dedicated snow tires last year, “I’ll never go another winter without putting on snow tires. The change in traction from the A/Ts I normally run on my trucks is amazingly better.”
Soft tread compounds and thousands of gripping surfaces around each tire make for very good vehicle control when Mother Nature brings on the white stuff.
When it comes time to swap out summer tires for the winter treads, replace all four. If you just put the tires with the better traction on the rear, you’ll be setting yourself up for some serious problems.
For example, put the tires with better traction on the rear of your pickup and it will “understeer” in a slippery corner, wanting to go straight instead of turn.
Likewise, putting new tires with better traction on the front of the truck and the back will tend to slide out (oversteer) in corners or when braking.
So when you replace tires, make sure all four are of the same type, size and condition to keep balanced vehicle handling.