A detailed experimental study to quantitatively compare a roll-plane hydraulically interconnected suspension with anti-roll bar in articulation (warp) mode is presented in this paper. Anti-roll bar as part of conventional vehicle suspension system is a standard configuration widely used in road vehicles to provide the essential roll-stiffness to enhance vehicle handling and safety during fast cornering. However the drawback of anti-roll bar is apparent that they limit the wheels' travel on uneven road surface and weaken the wheel/ground holding ability, particularly in articulation mode. Roll-plane Hydraulically Interconnected Suspension (HIS) system, as a potential replacement of anti-roll bar, could effectively increase vehicle roll-stiffness and provide the tunable damping effect, without compromising vehicle's flexibility in articulation mode. This paper presents the finding of an experimental analysis of roll-plane HIS system in comparison with anti-roll bar on a sport utility vehicle in articulation mode. The test vehicle has three different configurations for comparison: 1) conventional suspension without anti-roll bar, 2) with anti-roll bar, and 3) with roll-plane HIS. The test results demonstrate that in articulation mode, anti-roll bar limit wheel's travel, while HIS system has a negligible effect on wheel's travel. A detailed analysis and discussion of test results are provided to conclude the paper.