The cold snap and heavy snow that has blanketed much of the country this past week took millions of motorists by surprise – and sent many spinning off the road.
Winter can be treacherous, especially if you’re unprepared. The rise of the SUV offers some help, the majority of utility vehicles being sold today equipped with all-wheel-drive – with even a growing list of conventional sedans now offering the technology.
But AWD is only something of a band-aid. Staying safe while driving in cold, snowy weather is all about where the rubber meets the road – and the type of rubber that your car is shod with. There’s a reason experts often derisively refer to the ever-present all-season tire as “no season tires.” They’re simply a compromise that, when winter delivers its worst, can fall well short of what you need to keep your car on the road.
There was a time when American motorists routinely switched to so-called snow tires as the temperature dropped. Only a small percentage still do – which is ironic considering that winter tire technology has improved dramatically in recent years.
Bridgestone two decades ago introduced the transformative Blizzak which used a unique rubber compound and tread design to retain its grip on icy pavement. Similar tires are offered by virtually all of the major brands today.
But they’ve also gone significantly further, said Ian Coke, the chief technical officer with Pirelli North America. Today, you can pick from a fairly extensive menu of options that allow a motorist to match tires with not only their vehicle but the specific sorts of winter driving conditions they’re likely to face. In some cases, that might mean lots of snow, in others mostly icy roads.
“Winter tires aren’t just for snow” anymore, said Coke, during an interview with TheDetroitBureau.com.
They all have something in common, however. The rubber used in summer, as well as all-season, tires is sensitive to temperature and 44 degrees Fahrenheit, explained Coke, is “the transition point. Below that, rubber compounds tend to solidify,” which makes it harder for them to retain the necessary contact patch with the road – and their grip.
What all winter tires have in common is that compounds that remain soft, even at sub-zero temperatures. These “compounds are what have brought us to the point where they can maintain extra good performance in both the wet and snow,” Coke added, though those compounds can be tweaked for specific conditions
Engineers also work on a tire’s tread and lamella – the latter referring to the individual blocks of rubber that can flex as the tire hits the pavement. These patterns serve a variety of purposes but, in the end, the key is to maintain grip and ensure that snow doesn’t build up inside a tire’s treads.
While switching to winter tires can make a big difference, especially in places where snow and ice are the norm in cold weather, experts stress that motorists check to see what tires are recommended for their specific vehicle. You can have tires carry the same brand and model name, say a Bridgestone Blizzak or a Pirelli P Zero, but what’s right for one vehicle may be different for another due to subtle difference in tread design and rubber compounds.
In winter, maintenance becomes more important than ever. So, make sure to check inflation pressure and tire conditions, looking for any cuts or tears, or wear that might reduce traction.
Eventually, wherever you live, what is looking to be a long winter will finally give in to warmer weather. And the unique compounds that help winter tires perform so well can become a deficit.
“As temperatures increase, they become softer still,” stressed Pirelli’s Coke, “and wear begins to increase. We recommend you change back (to summer or all-season tires) once the weather becomes warmer than 44 degrees Fahrenheit regularly.”