Rod or bar that resists twisting and has a strong tendency to return to its original position when twisted. In an automobile, a torsion bar is a long spring-steel element with one end held rigidly to the frame and the other end twisted by a lever connected to the axle. It thus provides a spring action for the vehicle.
A Stabilizer Bar is a bar linking the two front suspension systems in order to help them resist sway. A stabilizer bar does not affect suspension stiffness when both wheels are deflected equally in the same direction.