Suspension roll characteristics are investigated using multi-body dynamic simulation software to analyze the handling stability of a coach air suspension system. Sensitivity analysis is applied to reveal the relationship between the guide mechanism geometry and roll center height of the suspension. The locations of V-pole mounts are adjusted to obtain a lower roll center position. The results of the steering wheel angle step input and steady-state circular tests are compared. To verify the effectiveness of vehicle model. Results indicate considerable improvement in handling stability, made possible by the low roll center height of the rear suspension.