If you’re at all thankful for our minimal snowfall this winter, at least until this week, thank me.
I was the one who, trying to be prepare early, jacked up my Volvo station wagon on a frigid December morning and swapped my all-season tires for a set of four winter tires. That pretty much assured our low-snow winter.
Why “all-season” tires aren’t enough
There could be great dumping ahead of us, as there is almost every February and March. And for the most part, drivers will venture out, confident that modern drivetrain designs like front-wheel and all-wheel drive will get them to their destinations without drama. Electronic aids like traction control, stability systems and antilock brakes further bolster their self-confidence.
But I learned early that there is no substitute for winter tires in conditions with heavy snow. Their tread design keeps your car from skidding during braking and while making turns. You won’t slide through stop signs; you won’t continue going straight when trying to turn. Simply put, the tires give you more control of the car, help keep you out of accidents and avoid the skidding cars that don’t have them. All-season tires, despite their name, fall one season short if it’s a season of heavy snow.
If it’s just a dusting of freshly fallen snow, all-season tires will probably be fine. Driving gets trickier, though, when traffic packs snow to concrete hardness and parking spots get burnished to skating-rink slickness. Which is why you need to have tires that are up to the task.
This is even true if there’s just a little winter slop. Those electronic assistants built into modern cars can limit the amount of power going to the wheels or the braking force during a skid, but improving traction requires a better match of tires to surface conditions.
Winter tires — what used to be called snow tires — stand apart from all-seasons or summer performance tires with deeper grooves, a distinct tread design and special recipes for the rubber. True winter tires carry a symbol on the sidewall depicting three mountain peaks with a snowflake inside.
Tread makes the difference
Unlike all-seasons, winter tires have an increased tread depth that helps channel away snow and slush and improves traction by packing snow in the tread grooves for what Bridgestone, the tire company, calls “snow-on-snow” traction. The idea is to take advantage of the stickiness that makes snowballs hang together.
More noticeable are the many added small slits, called sipes, in the tread surface. The sipes help the tire by presenting more edges that can dig into the snow for grip. Smaller voids in the rubber surface help to disperse the layer of water that often lies over snow. That’s also a significant benefit when the surface has turned to ice, like it’s done this winter.
What you won’t see, though, is the rubber chemistry tailored to cold-weather duties. Winter tires are engineered with softer compounds to remain flexible at far lower temperatures. While a summer performance tire becomes stiffer and loses grip as temperatures dip toward freezing, a winter tire stays pliable, making it superior even when the roads are dry.
The negative, though, is that the softer rubber increases tire wear on dry roads. A benefit of all-season tires, which maybe should be called “all-temperature” instead, is that they remain pliable in much colder conditions than summer tires can handle.
One more thing: You want to have winter tires at both the front and rear, no matter which wheels are doing the driving.
Why would you need winter rubber at the front if your car is rear-drive like my pre-turn-of-the-century wagon? It’s so you’ll be able to turn corners when the road gets slick. Likewise, traction is crucial for braking, which transfers weight onto the front tires. And having equal grip at both ends of the car, no matter which pair of wheels are powered, makes the reactions to turning and slowing more predictable and controllable.
They’re worth the hassle
Buying four tires — and ideally wheels to mount them on — is not cheap, usually about $ 1,000, and swapping them out twice a year is a hassle, but the safety and peace-of-mind benefits are considerable, especially if you have less-experienced teenagers driving. Owners can save money on having a garage do the swaps by mounting their winter tires on less-expensive plain steel wheels.
Ideally, it’s best to put some miles on a new set of winter tires before the snow falls. Typically, the manufacturing process includes the application of a lubricant to keep the rubber from sticking to the mold in which the tire is formed, and it can take some miles for this release agent to wear away.
And what do you do with those off-season tires? That’s a challenge for apartment dwellers, though some retailers offer storage. Homeowners, assuming they can clear space in the garage, should put tires away clean and dry, out of direct sunlight. An airtight storage bag is recommended, and if the tires are mounted on rims, store them standing on the tread surface.
One last reminder: The most important factor in safe winter driving is the person behind the wheel. You can find some helpful tips here to stay out of ditches and drive safely.
Smarter Driving is a new series all about how to buy, own, drive, and maintain your car better. Have something you’d like us to cover? Reach out to Smarter Driving’s editor, James Schembari, at firstname.lastname@example.org.