Have you ever wondered about just what criteria separates winter and summer tires? If you have, the following information should clear some things up for you. Specifically addressed here is the difference in temperature behaviors, rubber composition and tire markings between summer and winter tires. Once you read this through, you should have a better idea about these differences.
Temperature Behavior
Winter and summer tires have extremely different reactions to heat and cold. Winter tires are made of soft rubber that is appropriately soft at sub-freezing temperatures in order to grip icy and snow-covered roads. However, in the warmth of the summer, they can become too soft. You shouldn’t use winter tires until the temperature dips below 45 degrees Fahrenheit, which is about the same temperature at which you can see your breath (attention: consult your local legislature about compulsory use of winter tires in winter time. The regulations can be different from region to region). When you drive on summer tires at this temperature, the rubber will harden up and the tires will lose all their grip, even on dry pavement. Summer tires, however, are designed to be just soft enough in extreme heat to increase performance and prevent blowouts.
Difference In Rubber Composition
Though both summer and winter tires are made with a softer rubber than year-round tires, the compositions of those rubbers could not be more different.
Winter tires contain much more natural rubber within their compositions which prevents them from hardening in cold temperatures in the way synthetic rubber does. The compound deforms easier than that of summer tires allowing greater contact with the road’s surface.
The specialized synthetic rubbers used in summer tires is just like the type used in any high-performance tires. It increases your grip on the road and provides startling thread lock flexibility. The unique rubber composition and thread patterns allow greater precision when driving around corners and better responsiveness and braking capabilities.
Distinguishing Markings
Tire markings refer to all the information molded into the sidewalls of a tire. For example, if you see an icon that says “M+S,” that stands for “mud and snow”, so what you have is an all-season tire. This “tire code” on summer and winter tires is a bit different. There are no real designations for summer tires. Their only distinction is not having the “M+S” marking on them at all. Whereas, winter tires do have an “M+S” indicator, along with a logo consisting of a mountain and a snowflake.
winter sign
There are also markings that refer to the temperature, treadwear and traction ratings. Because it commonly known that winter tires are only useful below 45 degrees Fahrenheit, they do not have any type of temperature rating among their tire marks, but summer tires do. You will usually find temperature ratings marked as either an “A”, “B” or “C”. This is stamped below or to the side of the tire size. The “C” ranking has the least resistance to heat build-up, while “A” has the most.
The treadwear rating, using a number set between 100 and 700, provides information about how long a tire’s threading should be expected to last. The number “700” indicates the longest amount of time. Summer tires can have low treadwear ratings compared to all-season tires. Winter tires aren’t rated, but tend to wear just as quickly, however, due to being driven on ice and snow continuously. Also, treadwear can be accelerated couple of times if you use winter tire in summer time due to soft rubber composition. Doing this, you risk to, even for a brief period of hot weather, completely destroy winter tire for next snowy season.
The traction rating simply rates how well a given tire will grip a wet road, and it has nothing to do with typical performances on dry surfaces.
To Summarize
After mentioning all factors above the conclusion is obvious: for your own safety, use particular tire for particular season. All-season tires are best suited for moderate climate, with relatively warm winters and less weather change spikes. Just to know, at freezing temperatures and wet road, non winter tire can double braking distance, and cornering are more difficult. If you include snow in equitation, statistics go even more in favor winter tire.
The attributes and functions of summer and winter tires are quite distinct. Since you now know the differences in temperature reactions, rubber compounds and tire markings, you can feel comfortable purchasing both winter and summer tires that meet your needs.
