What does a car's suspension system do?

A car's suspension system allows for a smooth ride over rough roads, while ensuring the tires remain in contact with the ground and that body roll is minimized. It allows the car to travel smoothly over bumps in the road by absorbing and dissipating kinetic energy from the point of contact. Furthermore, a suspension system allows the car to turn corners without rolling by shifting the car's center of gravity to maintain balance. A key part of the suspension system is the shock absorber. Its job is to convert kinetic energy into heat that can be absorbed by the shock's hydraulic fluid.

Another key component of the suspension is the anti-sway bar (also known as an anti-roll bar), which connects the two sides of a car's suspension along the axle. If one side of the car moves up or down to any extent, the anti-sway bar is able to minimize the roll of the car by distributing the movement to the other side of the car. This means the car won't sway too much in either direction and will remain more level. The anti-sway bar is of particular use when going around corners, especially sharp ones.

Race car suspension systems make for an interesting contrast with standard cars. Although it's better and safer for both racing cars and standard cars to have all of their wheels in contact with the track or road at all times, and both use independent suspensions, the reasons they use them differ. The race car driver wants all four wheels to be on the track for stability, and so the wheels take advantage of the engine's power. The race car's suspension has to handle extreme acceleration and turns taken at high speeds and sudden stops, all of which are more than a standard car is built to deal with. The standard car's suspension, on the other hand, only has to deal with balancing comfort and performance.