How do steering and suspension systems work? – Three important principles

ย The most crucial component of a car is its steering and suspension system. No matter how powerful the engine is, the car’s performance is irrelevant if the driver can’t control it. The primary function of the suspension system is to maximize the friction between the road surface and the tires, ensuring steering stability and excellent handling.


As everyone has experienced, roads can be very bumpy. Even freshly paved roads can have imperfections that exert force on the wheels. When the wheel moves up and down due to irregularities on the road surface, the car experiences vertical acceleration as it passes over these imperfections. This phenomenon can be explained by Newtonโ€™s laws of motion, which state that all forces have both direction and magnitude. The extent of the vertical acceleration the car experiences depends on the size of the road’s irregularities.

Without a mechanism to manage the wheel’s vertical energy, this energy would be directly transferred to the car’s frame, causing it to move in the same direction. This can result in the tire losing contact with the road, and as gravity pulls the tires back down, they will slam onto the road surface. Therefore, a system is needed to absorb the wheel’s vertical energy to ensure the frame and body ride undisturbed while the tires encounter bumps on the road.

Engineers have identified three important principles to achieve this:

Road isolation refers to the ability of a vehicle’s suspension system to absorb and dissipate the energy from road irregularities, preventing these imperfections from being transmitted to the vehicle’s frame and passengers. Essentially, it is the suspension system’s capacity to isolate the car’s body from the bumps, dips, and vibrations of the road surface, ensuring a smoother and more comfortable ride. Effective road isolation enhances driving comfort and maintains the vehicle’s stability and control, even on uneven or rough terrain.

Cornering refers to the action of navigating a vehicle through a turn or bend in the road. It involves a combination of steering, acceleration, and braking to maintain control and stability while changing direction. Effective cornering requires a balance of speed and traction, with the car’s suspension system playing a crucial role in managing the forces acting on the vehicle. Key factors that influence cornering performance include the car’s weight distribution, tire grip, suspension setup, and driver skill. Good cornering ability enhances a vehicle’s handling characteristics, making it safer and more enjoyable to drive on winding roads.

Road holding, also known as road grip or handling, refers to a vehicle’s ability to maintain traction and stability on the road, especially during maneuvers such as cornering, accelerating, and braking. It is a critical aspect of a car’s performance, influencing how well the vehicle responds to driver inputs and how effectively it can navigate different driving conditions. Good road holding ensures that the tires remain in contact with the road surface, providing better control, safety, and overall driving dynamics. This attribute is largely influenced by the car’s suspension system, tire quality, and overall design.