This time of year, it's important to understand the difference between winter tires and all-season tires. Each type of tire serves a specific purpose. Winter tires are designed to provide maximum control and safety in snow, ice, and cold weather conditions. Many people believe that all-season tires can deliver this same performance, but this is simply not the case. While all-season tires are good in a number of general year-round driving conditions, performance can degrade significantly in cold and icy conditions.
The design
According to a
report by Ezine Articles, “the grooves on the winter tires are
made to be about 25% – 35% deeper than that of normal tires and
thus provide better grip." The depth of the groove allows a
greater surface area to come in contact with elements such as snow
and ice. The more surface area of the tread exposed, the greater
the ability for the tire to safely advance through the material.
Strategic lug and groove shapes allow more snow to be packed into
the tread and expelled as the tire rotates for better deep snow
traction. Furthermore, many winter tires are designed
with a rounder casing to add traction by cutting into the snow
surface.
Winter tires are also made of compounds which remain soft in colder weather. Softer tires are able to grip the road better. Often times, silica-based, micro pore compounds (or comparable technology) are used to bite through the water film and provide superior traction on snow and ice. This can dramatically improve your stopping distance. In many instances, this may be the difference needed to avoid a slippery accident.
All-season tires are constructed of very different rubber compounds. These compounds are “averaged" to deliver better wear and good traction in a wide range of conditions, but the trade-off is a decrease in traction below 40 degrees Fahrenheit. This is the point where all-season tire compounds begin to harden and lose traction.
As we discussed in an earlier article, proper winter tire can improve braking by up to 25 percent over an all-season radial and can improve collision avoidance by about 38 percent.
For winter driving safety, it's suggested to:
- Place winter tires on all four wheels
- Install winter tires on steel or winter-use rims. This allows for quick installation at a moment's notice and can reduce unnecessary tread wear
- Drive appropriately in weather conditions and give yourself the proper break distance
Only placing two winter tires on your vehicle is essentially useless. It's a false sense of security which you will not benefit from. The advantage of winter tires is that you've got solid traction on all four points which make road contact. If for some reason you can only put two winter tires on your vehicle, they must go on the rear axle.
According to the Rubber Manufacturers Association (RMA), shipments of winter tires have increased annually since 2003, from 6.3 million in 2003 to 9.5 million in 2009. This is reflective of the fact that more and more drivers are switching to winter tires for the winter season. Motorists may wonder how to determine exactly what kind of tires they have. The National Highway Traffic Safety Administration (NHTSA) recognized this as a source of confusion for many drivers and offered an explanation in a brochure about tire safety. The NHTSA brochure advised the public that “M+S" or “M/S" “indicates that the tire has some mud and snow capability." This can be especially important for residents of certain areas that receive extremely large amounts of snow because they may be required by local law to use “true snow tires, those with very deeply cut tread."
As we embrace the first few snow storms of the year, it's quickly time to prepare your vehicle for winter driving. If you have any questions about winter tires or driving safety, please feel free to call or stop by one of the convenient Dunn Tire locations.