MacPherson Strut Suspension

The MacPherson Strut Suspension is named after the developer Earle S. MacPherson. The MacPherson Strut Suspension was developed in 1947. In this type of suspension the upper part of the hub which houses the coil spring of the suspension and the shock absorber are housed in the strut proper which is connected rigidly to a mounting point in the body shell of the vehicle. The MacPherson strut has the steering arm built into the lower inner portion. The lower control arm is mounted onto the frame of the car. MacPherson struts consist of a wishbone which provides a bottom mounting point for the axle.

The MacPherson Strut Suspension requires substantial vertical space and a strong top mount. For this purpose a monocoque or unibody construction is required so that there is enough space to accommodate the MacPherson Strut Suspension. Because of its fairly simple setup it provides wide access to the engine bay for maintenance work with a detachable upper control arm. This type of suspension is ideal for front wheel drive small cars with transverse mounted engines. An anti-roll bar can also be integrated into the system for better handling traits. MacPherson Strut Suspension is a simple design which is cost effective because of which it is widely used in mass market cars.

The drawback of a MacPherson Strut Suspension is that front wheel cars tend to understeer under hard cornering by nature and the suspension setup tends to lean the body of the car under hard cornering which makes understeer worse. The suspension setup also tends to transfer a lot of road noise onto the body of a car because of which a lot of sound deadening material has to be used which increases the weight of the car thereby reducing fuel efficiency. MacPherson Strut Suspension does not offer good handling traits as it does not allow vertical movement of the wheel due to limited camber angle change and roll centre adjustment.