Science Files: Snow Tires and Traction
All Season Radials. Now there is a phrase! Maybe in Florida or California there is such a thing, but in Canada, especially, it seems this year, it is the height of folly to suppose that one set of tires will fill the bill and provide maximum safety where the rubber hits the road.
All that keeps a car from moving in straight line once it is up to speed is the four small patches of rubber we call tires. And on each tire you have perhaps 20 square inches on which the most incredible forces are exerted. On a corner its those tires you have to rely on. a patch of rubber ten by ten inches that have to hold a tonne and half of glass and steel and all its inertia at bay while you turn the wheel. In the process on dry pavement the cost is a a layer of rubber peeled from the surface of the tire. On snow or ice or water, the tire has less to grip and in a worst case scenario your car or truck makes use of Newton’s best physics and continues on in a straight line until it can find a more convenient way of unburdening itself of the excess energy.
That’s just for turning a corner. Stopping is a whole order of magnitude greater.
Driving is the biggest killer and producer of injuries we have control over. Each year some four thousand Canadians die because of car related injuries. By donning proper snow tires, studies tell us that 25% of winter collisions could be avoided. Add to that the cost to insurances and repairs, emergency infrastructure and rehabilitation to those injured and the cost begins to settle in.
Canada is the second coldest country in the world and snow and ice is a fact of life, even if there is climate change. Our way of life rides on our tires. Snow tires cost so little and can provide so much. Talk a second to look at the treads of your vehicle. Once a collision happens its too late. Physics is physics.
December 18th, 2007 at 11:07 am
Any chance you could comment on front wheel drive winter tires? I normally leave all season on the back and swap out the front with good winter tires. I could see it being slightly better to swap out all four, but the seems a question of price and effort to do all four.
January 15th, 2008 at 3:33 pm
very VERY true. i liked your article it was very informative. see im looking for any info on the physics of snow tires. For my Gd. 11 Physics class. if you have any more info it would be great if you could post some of it
Great Article
February 18th, 2008 at 4:58 am
Hey John
Not a good idea, especially with front wheel drives. Its not about getting up to speed traction, but the stability traction, going around corners, stopping and hydroplaning. When you have different grips on the road during inclement conditions the back end will ride out and through the car off the curve, Its is a deadly combination. You are better off with four not so good tires rather than two snows on the front with tires that don’t grip on the back, because you will not get going as fas in a straight line.