Mazda MX-6 - 4WS (Four Wheel Steering)

4WS (Four Wheel Steering)

Used from 1987 to 1998 on both MX-6 GT and GE models.
It was available on both the first generation and second generation MX-6 models, although the North American market only received it for the 1989 GT model. South African MX-6s never received 4WS.
According to Mazda, the system provided:

• Superior cornering stability
• Improved steering responsiveness and precision
• High-speed straight line stability
• Notable improvement in rapid lane-changing maneuvers
• Smaller turning radius and tight-space maneuverability at low vehicle speed range

The system electronically controlled a rear rack that was behind the rear wheels. At low speeds (of up to 35 km/h), the rear wheels would move in the opposite direction to the front wheels, aiding parking and U-turns by lowering the turning circle. Above these speeds, the rear wheels would move in the same direction as the fronts, meaning control during high speed maneuvers such as lane changes or cornering was improved. Either way, the turning angle of the rear wheels was slight at just five degrees, a measurement Mazda determined to be optimally effective and natural to human sensitivity.
Note:

• When the engine is turned off, the rear wheels would straighten up. They would change back to the angle of the front wheels when the engine is restarted. This is caused by the 4WS control unit powering down, and the fail safe system overriding the rear rack.
• If the system ever faults, as a fail safe the rear wheels would lock straight to allow the vehicle normal 2WS functionality.