What minimum tread depth is required by law?
But if the tread of the tire is too shallow, it will cause great harm to the car. If the tire tread is too shallow, not only will affect the ability of the water storage and drainage, but also easy to produce harmful "water skiing phenomenon", ("water skiing phenomenon": when the tire in the water containing layer on the road when rolling on water layer and crowding, tire and road surface contact area in front of the water because of inertia and generate dynamic pressure (and speed is proportional to the square). As the tire speed increases, the dynamic pressure reduces the direct contact between the tire and the road surface. And when the speed reaches a certain extent, the lift of the dynamic pressure is balanced with the vertical downward load, when the tire will completely lose contact with the road surface and float on the water film The disadvantages of light tire tread are easy to slip, so that the automobile performance mentioned earlier is deteriorated, so the harm of tread pattern is too great.
For example, the deeper the tread pattern, the greater the amount of elastic deformation of the pattern block, and the rolling resistance formed by the elastic hysteresis loss of the tire will also increase. That is to say when the tire contact with the ground, will consume part of the force to offset the elastic deformation caused by the tire tread too deep, will form a larger drag on the car, affect the power input and increase fuel consumption. And the deep tread pattern is not conducive to the tire heat, in the running process of the automobile, severe tire and ground friction will cause the tire temperature rises up, tearing off phenomenon, the root pattern due to force serious and easy to cause the tire.
The tread depth shall be checked according to the following standard:Good: greater than 3.5mmSuggest changing next time: 2.5~3.5mmNeeds to be replaced: less than 2.5mmReplacement limit: 1.6mmIf the tires are old and cracked badly, they should be replaced early.
The national standard stipulates that the wear limit of radial tire tread for passenger cars is 1.6mm, and the wear limit of radial tire tread for trucks and coaches is 2.0mm.
Therefore, the depth of the tread pattern has great influence on the driving of the car, whether the tread pattern is too deep or too shallow is not good. The objective law is that the patterns will be smaller and smaller in use. In order to ensure the effectiveness of the pattern effect, all countries in the world on tire wear limit has made clear regulations, and in the tire shoulder along the circumference of the plurality of parts mold carved tire wear limit alarm mark, when the marking pattern has been removed, revealed a narrow horizontal strip of light tread, so as to alert the driver. The tire has to be replaced time.
