Ride control

Ride quality refers to the degree of protection offered vehicle occupants from uneven elements in the road surface, or the terrain if driving off-road. A car with very good ride quality is also a comfortable car to ride in. Cars which disturb vehicle occupants with major or minor road irregularities would be judged to have low ride quality. Key factors for ride quality are vibration and noise.

While pleasant, the comfort of the vehicle driver is also important for car safety, both because of driver fatigue on long journeys in uncomfortable vehicles, and also because road disruption can impact the driver's ability to control the vehicle.

Automakers often perceive providing an adequate degree of ride quality as a compromise with car handling, because cars with firm suspension offer more roll stiffness, keeping the tires more perpendicular to the road. Similarly, a lower center of gravity is more ideal for handling, but low bodywork forces the driver's and passengers' legs more forward and less down, and low ground clearance limits suspension travel, requiring stiffer springs.

Ride quality is also related to good braking and acceleration on poor surfaces. It protects the car itself, as well as its passengers and cargo, from vibration that might eventually damage or loosen components of the car.

Ambulances have a special need for a high level of ride quality, in order to avoid further high speed travel related damage to the already ill passengers.

Early vehicles, like the Ford Model T, with its leaf spring, live axle suspension design, were both uncomfortable and handled poorly.

Historically, weight was key to allowing cars such as the Rolls-Royce Silver Cloud and the Cadillac in the 1950s and 1960s to have a more comfortable ride quality. The downside is that weight also contributes to poor fuel efficiency. From simple physics, soft ride is actually caused by the ratio of the weight to the spring stiffness.

In most of the world, the high price of gasoline effectively prevents most motorists from using massively heavy cars.

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Wikipedia