- A coilover, short for coil spring over strut, is a device used in automobile suspension systems that is essentially comprised of a shock absorber encircled by a coil spring. A shock absorber is a mechanical device used to help absorb the shock caused by sudden acceleration or deceleration. A coil spring is used to absorb shock by storing energy and later releasing it.
- A coilover increases the weight capacity that a vehicle can haul and load. Coilovers also allow for increased towing capacity, and help control weight distribution of a towed mass. Coilover devices allow for better off-road handling, as they absorb the shocks produced by traveling over rough or uneven terrain.
- Coilovers may use a spring perch, or an adjustable two-part nut, to adjust the ride height, or ground clearance between the base of the tires and car chassis. Coilovers may also use a shock body, which uses a lower mount to adjust for ride height, and an adjustment knob used to adjust for damping, or shock absorption.