zig@tr

Winter tires are much different in composition and design from an all-season tire. The all-season tire has always been the "all purpose" tool of the tire industry, built to have the ability to be used when road temperatures are over 100 degrees and below zero degrees and can provide traction in all weather conditions. This wide range of abilities is very attractive to many buyers as there is no need to change tires when the seasons change, making the all-season tire an easier less expensive option.

This "all purpose" attribute is also the all-season tire's biggest disadvantage, this type of tire is asked to do a little of everything and because of this it can only do a "little" of everything. If you can image that every tire has only 100 points to be distributed among every driving condition, the all-season tires would roughly have all points distributed evenly across all driving conditions. This may leave you with only a small amount of points for ice and snow traction once you have given points to all of the areas this all-season tire must be able to perform. Whereas, a dedicated winter tire has a very specific job and can give all 100 points to ice, snow and cold weather driving.

These dedicated winter tires have a soft rubber compound designed to stay soft and pliable in colder temperatures which will conform more readily to variations in the road and packed snow and ice. Also, a higher silica content for a grittier texture and large amount of siping to created as many biting edges as possible. I have a series of illustrations below which will help explain the design and application of dedicated winter tires:


A very simple illustration uses these foam blocks. Imagine this is a microscopic view with the gray bottom layer representing the road surface, the white middle layer representing ice or smooth packed snow on the road surface, and the black top layer representing your tire. The black foam block depicts a dedicated winter tire, the deep vertical groves in the tire are called sipes, an all-season tire has a small fraction of the sipes a winter tire will have. The sipes in an all-season tire will not be as deep and in some cases can be completely worn off by the time you reach 8/32". As you can see not much to grip and with all-season tires that will remain stiff in these cold temperatures.....this is all the traction you will get!



As illustrated below, during accelerating, braking and cornering the winter tire will flex at each of these sipes creating thousands of tiny biting edges. This function combined with the higher silica content and softer cold weather rubber will keep the tire getting traction beyond the limits of an all-season tire.



Here is a close-up of the siping as it would appear on an actual dedicated winter tire.



Tire Rack also recommends that drivers expecting to encounter snow-covered roads consider replacing their tires when they reach approximately 6/32" of remaining tread depth to maintain good mobility. Tires need more tread depth in wintry conditions to compress snow in their grooves and release it as they roll. If there isn't sufficient tread depth, the "bites" of snow that can be processed on each tire revolution will be reduced to "nibbles," and the vehicle's traction and mobility in snow will be reduced.



It's also important to note that the recent advancements in electronic driver aids, such as ABS and traction control don't provide more traction. They only help prevent drivers from over braking or overpowering the available traction of their tires. The only thing the driver can do to increase traction...to actually get more grip and control... is install better tires for their specific traction needs.

All-Season Tire Winter Tire




Winter Tire and Wheel Link


Please take a look at the winter tire/wheel options we have available for your specific vehicle and give me a call at 800-428-8355 Ext 784 or send an email to zig@tirerack.com if you have any questions.

BIGCARL78

Thanks for the info.

Gjohnson

Very informative.