Coilover shocks are built with a coil that is wrapped around the shock body of a vehicle. This coil acts like the coil springs on a suspension, and will give tighter highway handling with less swaying. The shock absorber's ability to control the rocking motion caused by wind at speed will be increased by the heavy coil springs.
Coilover style absorbers also increase the amount of weight that can be safely loaded and hauled with the vehicle. As the weight goes up, the coils assist the vehicle's stock springs with carrying the load, up to 500 pounds per coil.
The coil added to coilover shocks makes towing heavy trailers easier, and safer. The coils add to the towing weight range of the stock suspension, and help control the towed mass around corners or on bumpy roads.
Four-by-4 enthusiasts often add coilover shocks to a rig to give it better handling off-road. The coils can absorb hard jolts that would overcome many stock shocks, and rebound more quickly. The coils on these vehicles are often painted for aesthetic enhancement.
