In order to improve the driving comfort of a car, shock absorbers are fitted inside the suspension system of most cars.

The damping system of a car is composed of a spring and a shock absorber together. The shock absorber is not used to support the weight of the body, but to suppress the shock when the spring absorbs the shock and bounces back and absorbs the energy of the road impact. The spring acts as a shock absorber, changing the "large energy impact" into a "small energy impact", while the shock absorber is gradually reducing the "small energy impact". If you have ever driven a car with a broken damper, you will be able to experience the bounce of the car through each pothole, after the undulation, and the damper is used to suppress this bounce. Without the damper, the spring bounce cannot be controlled, and the car will bounce badly when encountering rough roads, and will lose tire grip and traction when cornering due to the up and down vibration of the spring.

Hydraulic shock absorbers are widely used in automobile suspension systems. The principle is that when the frame and the axle do reciprocating relative movement and the piston moves in the cylinder of the shock absorber, the fluid in the shock absorber shell repeatedly flows from the inner cavity to another inner cavity through some narrow orifices. At this time, the friction between the liquid and the inner wall and the internal friction of the liquid molecules will form the damping force on the vibration.