Do winter tires really make a difference?

Check this chart to determine which tires work best in the winter months.

Check this chart to determine which tires work best in the winter months.

 

It can be a bit disquieting to consider that the only connection between your vehicle and the road are four relatively tiny patches of rubber. Start, stop or turn and you are at the mercy of the tires to follow your commands.

That’s why it is very important for owners of cars and trucks to make sure that they have the right tires for the conditions in which they normally drive. It is also important to regularly check tire pressure, the condition of the tires and the amount of tread on them.

But let’s face it. Most of us don’t think too much about the tires on our personal vehicles. The bulk of passenger vehicles seem to come with all-season rubber so we assume them to be up to the job and promptly forget about them.

We are wrong.

These points were brought home to a couple dozen automotive journalists who traveled to South Bend, IN, for a two-day program, Embrace Winter, conducted by tire maker Michelin and Tire Rack, the largest seller of tires directly to consumers in the United States and the largest independent tire tester.

The results of the company’s tests of tires from all major manufacturers are posted on the company’s Tire Decision Guide, available at tirerack.com, to help buyers decide which tires can best fit their needs.

The specific purpose of the South Bend meeting was to demonstrate that motorists in a large part of the United States should mount dedicated winter tires on their vehicles in the bad weather months, defined basically as October through March.

Check the above map and you will see that all-season tires are satisfactory only in parts of the United States that experience mostly moderate winter temperatures and only an occasional light or slushy snow. Some folks, those who live near the southern border, can even get along all year round on summer tires.

No surprise here. The red car has the dedicated winter tires.

No surprise here. The red car has the dedicated winter tires.

To demonstrate the superiority of winter tires over all-season tires, the journalists were taken to ice hockey rinks on the campus of nearby University of Notre Dame.

On one ice-covered rink were two identical front-wheel-drive Toyota Camrys, one with all-season Michelin tires, the other with the company’s top-of-the-line X-ICE Xi3 winter tires.

On the second rink were two all-wheel-drive Toyota RAV4 sport-utility vehicles, similarly equipped with all-season or winter tires.

The journalists took turns in all four Toyotas, with side-by-side drag races. The vehicles raced at full acceleration from one end of the rink to the middle, then slammed on the brakes.

All the vehicles moved slowly as the vehicles drive wheels spun on the slick surface and then skidded to a stop with anti-lock mechanisms working overtime. The results of these short races were predictable and convincing. The vehicles with winter tires picked up more speed and stopped in a shorter distance.

In a third test, Tire Rack drivers, driving side-by-side in the RAV4s, made 180-degree turns on the ice. The one with all-season tires skidded wide of its intended path, while the vehicle with winter tires made the turn without any loss of control.

To emphasize the value of winter tires, representatives of both companies agreed that a rear-wheel-drive vehicle with four dedicated winter tires, will perform better in bad weather than an all-wheel-drive vehicle with all-season tires.

So what specifically makes the winter tires enhance the grip on slushy, snowy and ice roads? Three things, according to the sponsors of the event.

First, the tire compound. Summer tires lose their flexibility as temperatures dip and will experience a serious loss of grip below 40 degrees,according to the Michelin representatives. All-season tires will also lose their flexibility in cold weather, but not as severely. On the other hand, the rubber compound in dedicated winter tires retains its flexibility in much lower temperatures, giving them enhanced grip.

The Michelin Man was on hand to spread good will for the boss.

The Michelin Man was on hand to spread good will for the boss.

Second the tread itself. A comparison of winter tires to others shows a much different tread pattern, Winter tires are specifically designed to bite into snow and ice, thereby enhancing the grip. They have numerous small cuts across the treads, which are known as sipes. When the tires reach the road surface, their sharp edges bite into the snow or ice and improve traction. Meanwhile, tiny holes in the tread, known as micro pumps, can vacuum away the last tiny layer of water that separates the tire from the road surface.

But, enough about the science. The important thing to note is that dedicated winter tires will safely get you through bad weather better than all-season or summer tires.

Okay, but what about the cost?

Michelin representatives mentioned an average price of about $1,000 per set of four, an amount that would generally be less than the cost of a fender bender and definitely a lot less than a more serious accident.

They agreed that the winter tires have only about half the expected tread life of a summer tire but pointed out that during the approximately four to five months they are on the automobile, they are replacing the original equipment rubber, thereby extending the life of those tires.

Both Tire Rack and Michelin executives emphasized the importance of regular tire-pressure checks, noting that tire pressure changes about one pound per square inch for every 10-degree change in temperature.

They also emphasized the need for a change in driving habits when the roads are covered slush, snow and ice. Drivers should maintain a greater distance behind the car in front and they should drive as smoothly as possible.

“Accelerate, brake and steer as if you had a full cup of hot coffee on the dashboard,” advised the Tire Rack testers.