What is the Difference between a Summer Tire and a Winter Tire?

There are always many doubts about the benefits of summer and winter tires, but theory and practice have given us the result that there are great differences between one and the other. BMW has already been in charge of teaching us first-hand that there is a disparity in the results of summer compounds compared to winter ones in different climatic situations, but today in this article we are going to see the main difference between both of them.

Summer tires provide better performance in the warmer months. They have a relatively hard compound that softens in milder temperatures to suit both dry and wet roads. They also have less tread than winter tires, although this one has been specially designed to minimize the hydroplaning effect, and provide more grip both longitudinally and laterally in warm temperatures, ensuring traction on wet and dry roads.

However, although summer tires can withstand most weather conditions, they are not suitable for cold climates. Due to the stiffer nature, with less natural rubber than winter ones, the rubber begins to harden to even brittle below seven degrees Celsius. They are also going to cope with higher temperatures without going soft, which means that summer tires have less friction and are therefore more efficient.

The latter in fact tent to have a relatively simple tread pattern, which provides a large footprint on the road. This ensures excellent handling and has a massive impact on stopping distance. It’s not just about making sure a tire can cut its ways through snow or scorching asphalt, it’s about making sure the rubber itself can perform in both low and high temperatures.

To visually differentiate them, a winter tire can be quickly identified by having a snowflake-shaped symbol on a mountain on its sidewall, indicating that it meets the safety criteria for winter conditions. For the avoidance of doubt, below we will break down the main difference winter and summer tires.

Grip and Driving Dynamics:

Winter tires are made with higher silica content as compared to the summer tires. The silica in the rubber means that they are less likely to harden when you hit the road on ice, achieving a better grip on any part of the road surface. If the asphalt is completely covered in snow/ or ice, the traction is also better. On the contrary, if the asphalt temperature is equal to or higher than 45 degrees, the summer rubber will move like a fish in the water.

We can, therefore, say that summer tires are less efficient when it comes to tackling the snowy terrain, and that is much more likely to turn when they are struggling on a layer of ice and trying to start off. This is why it is always recommended to start at the longest possible gear ratio and play with the clutch as long as your vehicle has a manual transmission.  And if the condition is not favorable, not all-wheel drive will save you.

Another difference between the winter tires and summer tires is that the former must be changed when their tread reaches a depth of 4 millimeters, while 3mm is the minimum recommended for summer tires. The stopping distance increases as the depth of the tread decreases. So a new tire, with an 8mm tread, will stop faster than one at 4mm and of course considerably faster than one at just 1.6mm.

In fact, once the tread has worn below 4mm, the benefits of the winter tire have little to no effect on snow or ice. And in case you are suddenly thinking why not use winter tires all year around, remember that above 7 degrees they will heat up too quickly and that affects their wear rate.

Efficiency in the Use of Fuel:

As we mentioned above winter tires are softer, even when the temperature is low, they get a better grip. This is an important safety measure, as it allows drivers to brake with greater guarantees, Nor should we overlook that fact that winter footwear is also allowed better handling on ice, without the wheel spinning, and that also means that the vehicle is more efficient when it comes to the consuming energy.

It is these differences in weather conditions and the way compounds behave that have led tire manufactures to spend millions of dollars each year in researching and developing materials that optimize the performance of the winter tires, specifically designed to deliver the best performance in cold weather condition, and summer tire compounds, which perform optimally throughout the rest of the year.