It is now widely accepted that electronically controlled suspension systems can offer substantial improvements over passive designs. However, much of the published work is based on idealised, theoretical calculations and practical developments have indicated that component limitations play a major part in governing the potential benefits available.In this work, the detailed response characteristics of a three-state switchable damper are first measured on a laboratory rig. The switching dynamics between states are characterised for both bump and rebound behaviour. Then, the performance of this damper in combination with a self levelling, hydro-pneumatic suspension is examined both theoretically and experimentally using a quarter vehicle rig. The issue of compensating for component limitations in the control system design is examined and shown to be an important feature in extracting the best ride performance from switchable damper systems.