The weather is getting cold, but not everyplace has seen its first snowfall. While the threat of snow is what gets most people thinking about putting winter tires on their cars, if you’re waiting for snow before you make the switch, then you’re waiting too long.

Winter tires or snow tires?

These terms are used interchangeably, which is why so many people wrongly assume the sole reason for switching tires in the winter is the snow. Winter tires are called winter tires because they’re designed to handle not just snow, but cold.

That means you don’t have to wait for the first snow to put winter tires on your car. As a rule of thumb, when the weather is consistently below 40 degrees, then you should use winter tires even if the sun is shining and there’s not a snowflake in sight.

Tires and candy bars

Imagine your favorite candy bar. At room temperature it’s just right. Leave that same candy bar in your car on a summer day and it becomes a gooey mess that ends up all over your shirt. Put it in the freezer, and it gets so hard you need a knife to snap off a piece.

The rubber in tires is just like that candy bar. It’s soft and pliant on a hot summer day, while winter weather makes it stiff and brittle. Winter tires are made of rubber compounds specifically designed to stay flexible even when it’s cold and that’s essential for good traction.

The importance of the contact patch

While a tire is big, its contact patch is small. This is the part of a tire that’s touching the road at any single moment. Take a piece of 8.5-by-11 paper and fold it in half. Now fold it in half again and what you have in your hands is about the size of the contact patch.

That small piece of paper is all the tire surface that’s available to grip the road at any one time. This is why maximizing each tire’s grip is essential. Having a winter tire with its more flexible rubber compounds is key to maintaining that grip.

Winter tire treads are different

The unique rubber compound of a winter tire is only part of the picture. These tires also have unique treads designed to handle the snow. The pattern of the tread is designed to wick away water, but to attract snow. This sounds odd, but with explanation it makes sense.

If you roll a snowball along the ground it sticks to the snow. A tire that collects snow in its treads mimics that snowball by sticking to the snow on a snow-covered road rather than just sliding across the top. This again gives you better grip and better grip is what you want from winter tires.

What about all-season tires?

There’s nothing wrong with all-season tires. They do the job in all seasons as the name implies, but that requires compromise. Since they have to work in everything from summer heatwaves to arctic winter blasts, they can’t excel at either.

If your weather doesn’t come with extremes of cold or heat, then an all-season tire is a more viable option. If, however, temperatures below 40 degrees are commonplace during the winter months where you live, then a winter tire is a far better choice.

- Nicole Wakelin/BestRide.com

DID YOU KNOW

U.S. was slow to adopt new headlights

Halogen made its way to the United States officially in 1983, approximately 20 years after it had been introduced in Europe, and composite headlamps started to appear in the 1984 model year.

We were similarly years behind with high-intensity discharge headlamps. HIDs had been in use commercially for years, but early versions had long startup times, which was fine in a commercial building, but not good in a car, which requires headlamps to turn on instantly, sometimes multiple times in a single trip.

Those issues were solved by the mid-1980s, and automotive engineers around the world went to work designing headlamps that could take advantage of the technology. European engineers used the H4 halogen light source and then brighter xenon-gas bulbs, and newly developed optical computer-lighting programs allowed smooth, computer-generated surfaces to form the beam pattern without having any optics in the lens.

These HID lamps are fantastic at throwing light, but they often throw it where it’s not wanted, specifically in the eyes of oncoming drivers. Again, Europe figured this stuff out years ago, while we’re literally blindly bumbling along with the same regulations we had when George W. Bush was still in office.

- Craig Fitzgerald/BestRide.com

CAR FACT

The Infiniti brand first appeared on the scene 30 years ago, back in 1989. That year marked the debut of “The Simpsons” and the fall of the Berlin Wall. You could fill up your tank for about $1 a gallon and the median price of a new house was only $125,000.

- Nicole Wakelin/BestRide.com