There are such patterns on the car tires, which is not for the sake of good looks, but to ensure the safety of the vehicle. It can make the tires "engraved" the pattern, only rubber can do it.
If the car is only driving on a very dry road, it is safe to not have a pattern on the tire. It can be slippery when there is no rain on a rainy day. This is because there is a thin film of water between the road surface and the tire, and the water film reduces the friction between the tire and the road surface. At this time, the car will sway when it is opened, but it will stop and stop.
If there is a pattern on the tire, the water will drain out of the groove of the pattern, and the tire and the ground will still stick tightly together, so it is not easy to slip. Vehicles traveling in the city, the patterns on the tires are generally linear sawtooth type, it can also help eliminate the noise generated when the car starts. In the wilderness of the vehicle, the pattern on the tire is deep and wide, and it can “bite” the ground tightly. Even if it is driving on snow, it is not easy to slip.