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Renault Laguna GT

By Simon Bickerstaffe

Four-wheel steering could be making a comeback. It appeared in the 1980s, turning up on unlikely contenders such as the Honda Prelude, Mazda 626 and Mitsubishi Galant, as well as the more overtly sporting Nissan Skyline. GM introduced Delphi’s “Quadrasteer” system on a number of full size pick-up trucks and SUVs in 2002.



Nissan still offers the technology on the Fuga luxury sedan and several Infiniti models. But while four-wheel steering has never really gone away, it hasn’t exactly caught on either.
Renault is the latest to introduce the technology to its customers. The range-topping Laguna GT comes as standard with “Active Drive”, Renault’s name for its electronically controlled active rear steering. The system will also feature on some versions of the Laguna coupe.

Renault says that that four-wheel steering improves the Laguna’s driving dynamics through better handling and steering. Manoeuvring becomes easier because the turning circle is smaller.

Active safety also improves. Electronic control means that transients are handled much better than by the mechanical systems of the 80s. Networking the system to ESC and ABS makes it even more effective.

But Renault seems to be out of step with other OEMs who have taken more conventional measures to improve the chassis. Multi-link suspension, electronically controlled dampers and four wheel drive are widely used elsewhere. Torque vectoring differentials are catching on too, so why bother with four-wheel steering?

Cost. Since the car’s introduction in 1994, Lagunas have always used a simple torsion beam rear suspension. The current model uses a modified version of the 2002 platform, saving Renault €100 million but leaving it as the only brand in the segment still using a twist axle.

As a result the basic Laguna may be a little less engaging to drive on twisty roads than some of the competition but ride comfort is superb – a key attribute for the families who still represent a significant share of Renault’s customers.

The carmaker’s performance hatchbacks also demonstrate that a torsion beam can provide excellent handling in smaller cars – the Renaultsport Clio and Megane are widely praised for the way they go round corners.

Renault accepts though that D-segment buyers coming from other brands will seek greater sophistication. It had to find a modular technology it could add where necessary without affecting the cost of the base model.

Four wheel steering was the chosen solution and at least gives the firm a unique technology in this vehicle class. Packaging is better than four wheel-drive or multilink suspension.
The system was developed by Renault and its performance division Renault Sport. Aisin of Japan supplies the actuator and controller, which are mounted directly to the axle beam.



At speeds up to 61km/h the rear wheels pivot in the opposite direction to the fronts by as much as 3.5°. At higher speeds they steer the same direction, by up to 2.0°, increasing to 3.5° during emergency manoeuvres. Under split-mu braking the system adjusts the rear steer angles to counter vehicle yaw and the ESC system is recalibrated to intervene at a higher threshold.

Driving the car along the mountain roads around Figari in southern Corsica left a good impression. The Laguna’s ace card – ride comfort – remains intact, improving if anything. The revised damper settings provide better body control.
Yet you can throw the car into bends at greater speeds than you might expect of this family sedan. The GT requires smaller steering inputs than the standard Laguna. Go faster and you can feel the back end turning, keeping the car on line.
The car still cossets the driver on long journeys. Despite stiffer springs and anti-roll bars and big 225/45 R18 Bridgestone Potenza tyres, very little noise or harshness passes into the cabin.

Renault quoted one emergency manoeuvre in particular to illustrate the system’s effectiveness. “We have very good results in the elk test,” says deputy chief vehicle engineer Serge Lacaze. “Our target was to have the same performance as the Porsche Boxster, but in the end we passed the test 5km/h faster.”

How consumers will react to the Laguna GT remains to be seen. With so much established competition in the sports saloon market, Renault is going to have a tough time.
Four-wheel steering on the forthcoming Laguna coupe could be a different proposition altogether. The car will probably sell on looks alone, but the option of V6 engines and Active Drive make it even more attractive.

A Renaultsport version – Renault says it has yet to make any decision on this – would not only find more customers for four-wheel steering technology, but the brand would have a genuine halo model.

Early four-wheel steering systems lacked the finesse to work well in all conditions and were expensive. The electronic control of today’s systems changes that – they are more capable, more reliable and cheaper too. But if the Renault-Nissan alliance remains the only adopters, four-wheel steering is unlikely to have any wider impact on chassis design now than it did in the 1980s.