The U.S. Army initiated program to assess the performance potential of a semiactive advanced suspension system for its combat vehicles is addressed. This paper is a continuation of SAE paper 970386, “Semiactive Suspension: A Mobility Case Study”, Saxon, N.L. and Meldrum, W.R. Jr. This year's paper addresses actual field testing of the semiactive hydropneumatic suspension versus a standard torsion bar passive suspension on two similarly weighted Bradley Fighting Vehicles. The hardware discussed will include semiactive external in-arm hydropneumatic suspension, computer controller, and dynamic track tensioner. The relative mobility of the two systems, passive and semiactive, is evaluated through various field tests such as ride, shock, slalom, and traverse testing. The proposed benefits gained from a semiactive suspension include faster cross country speeds, increased ride quality and platform stability, decreased shock loads to the hull, and increased crew comfort/operational effectiveness. The quantitative and qualitative performance benefits are evaluated through acceleration, velocity, and video data taken during testing. Computer modeling and mobility simulations of the two systems is also addressed to support field testing conclusions.