Self-Leveling and Ride-Height Control
Self-leveling and ride-height control are suspension functions that change the vehicle's static body height, but they do not necessarily provide high-bandwidth active body control.
Main functions
- Self-leveling restores a target height after passengers, cargo, or a trailer change the load. It can use air springs, hydraulic pressure, or a mechanically pumped leveling damper.
- Selectable ride height raises or lowers the body for ground clearance, easier entry or loading, aerodynamic drag reduction, or a chosen drive mode.
- Automatic height control changes height according to speed, load, location, or other vehicle conditions without a separate driver command.
How the functions differ
These systems manage the body position over a relatively long time scale. The available adjustment range, axle coverage, load capacity, and time needed to reach the target height vary by design. ZF's Nivomat, for example, uses wheel-to-body movement to pump a rear leveling unit without additional electronics.
Ride-height control should not be confused with semi-active damping or fully active suspension. A system may change height yet retain passive dampers, while a fast powered actuator can control pitch, roll, or individual wheel motion without relying on a slow height change. Some vehicles combine several of these functions. For the full classification, see Active suspension.