At the moment, the Renault company is rekindling an old subject with their Laguna GT. As early as 1992 we know of the hydraulic element in the BMW 850 CSI which enables a limited amount of steering of the rear the wheels depending on the steering angle of the front wheels. The difference to today however, is only the smaller turning angle, compared with the of 2008 of approx. 3,5°. The rear axle of the BMW is also driven, the axle of the Laguna isn't.

The hardware is relative simple. In the above picture you can see how a simple trailing arm suspension can be steered by the arrangement of the rear wheels, without influencing other which use the same basic undercarriage. The hydraulic cylinder in front of the cross-beam provides, by way of a two armed leverages and through a large gear ratio, for the sensitive movement of both tie-rods.

The rest is left to the electronics. Up to now, the Renault engineers have decided, that up to a speed of 60 kmh, the rear wheels steer in the opposite direction to the front wheels, above 60 kmh they steer in the same direction. This allows more agility with an approx. 10% smaller turning circle in and higher cornering speeds with increased saftey when driving faster on winding roads. In this case by the way, as a rule, only 2° of steering angle are achieved. In special situations, the electronics can add the remaining 1,5°.

By the way, up to now the system doesn't mean a thing when parking in reverse because the electronics refuse to go along with it. One gets the impression that Renault wishes, under all circumstances, to avoid the driver having to cope with anything unusual. The 'Bum-meter' could be irritated if the axle were to be too independent, that would then be the opposite of increased safety. However, upgrading per software is still conceivable without problems after the introduction. 06/08