This book introduces the methodology for conceiving, designing, optimization, and analyzing of the suspension and steering systems for four wheel drive and four wheel steered terrain vehicle. The suspension system design has derived from classical double wishbone control arm. Greater wheel motion has been ensured without reducing driving performance. In order to improve the driving comfort and safety an optimal active damping force has been determined by the active and semi-active systems. On the basis of comprehensive analysis, active system adequacy has been achieved. The suspension design provides relatively small lateral wheel motion, zero camber angles, and it effectively absorbs the vibrations caused by road configurations. The steering system design provides higher maneuverability at low speed and suitable stability at higher speed. This has been ensured by two modes of steering, all wheels steer and front wheel steer. The steering mechanisms conform to Ackermann law for all modes and situations. A totally new steering concept has been developed. This effective design consists of special pairs of gears, known as¿ non-circular gears¿.