When a vehicle with rigid axle suspension encounters road irregularities, the axle tilts and the wheels no longer remain vertical. This causes the whole of the vehicle to tilt on one side. Such a state of affairs is not desirable. Apart from causing rough ride, it causes wheel wobble. The road adhesion is also decreased. To avoid the wheels are sprung independent of each other, so that tilting of one does not affect the other. Besides, the independent suspension also has the following advantages over the rigid axle type suspension.

1. The elastic strain energy per unit spring weight stored in a coil or torsion bar spring is greater than in case of a semi elliptical leaf spring, which means lighter springs can be used in case of independent suspension.

2. In case of independent suspension, unsprung weight is reduced, which ultimately reduces the tire scrub and hence increases tyre life.

3. Compared to the rigid axle type. softer springs can be used without increasing rolling effects. Softer springs improve the ride comfort.

when anti roll bar is used in independent suspension, spring employed maybe even softer, as in the event of vehicle cornering, the anti roll bar will provide the forces necessary to resist body roll.

4. Improved steering precision since wheel movements are not linked. Gyroscopic action is reduced and the wheel travel path is controlled more accurately.

5. In case of independent suspension it is possible to locate the springs apart enough to obtain understeer conditions, which is always preferred to oversteer condition.

6. With independent suspension, steering geometry is not altered with spring deflection as in case of conventional rigid axle suspension where effect is specially noticeable during braking or acceleration.

7. Since in this there is no solid axle beam, which required clearance for its vertical movements, the engine and the chasis frame can be placed relative lower which means engine position can be moved forward resulting in more space for passengers.

Apart from the distinct advantages which the independent suspension possesses, it has its own drawbacks also :-

1. The initial cost is high.

2. Greater maintenance required because of large number of bearings.

3. Misalignment of steering geometry with the wear of components, thus requiring more frequent attention.

4. In the event of body roll, the wheels camber (tilt outwards in the case of wishbone type and inwards in case of McPherson strut type), due to which cornering power is reduced.

5. More rigid sub frame or chasis frame is required.

6. Forces due to unbalanced wheels are more pronounced and transmitted easily to the steering wheel.