The U.S. Army has initiated a program to assess the performance potential of a semiactive advanced suspension system for its combat vehicles. The program utilizes the Bradley Fighting Vehicle as a test bed for a semiactive external in-arm hydropneumatic suspension. The system hardware includes the suspension and associated plumbing, computer controller, and dynamic track tensioner. This paper describes the comparable benefits of the semiactive suspension over the passive suspension through both laboratory testing and simulation results. Transmissibility analysis of the laboratory data document far less hull motion in the semiactive case. Simulated vehicle mobility again shows less vehicle motion and superior ride quality using the semiactive suspension.