Automobile tyre tends to flatness

Nowadays the tyre tends to flatness, which indicating shortening between rim and tyre shoulder.
　　
Flatness of the tyre accords with people’s demand for safety. The first advantage of flat tyre is good heat emission, favorable to improvement of smoothness and reverse stability of the automobile. And due to its flatness, the tyre is firm and secure, decreasing possibility of the tyre to go flat. And it is also with disadvantages. Sine contact area increases between tyre and the road, running resistance of the automobile increases and oil consumption increases, too. And price is a little expensive.