New Active Drive With Four-Wheel Steering For New Renault Laguna GT
9th April, 2008
Europe's stylish, expressive Renault Laguna GT introduces the new Active Drive chassis with four-wheel steering (4WS), developed jointly by Renault and Renault Sport Technologies to yield the ultimate in driving pleasure, as regards handling, response and precision. Its sporty calling is further enhanced by the availability of two exclusive, high-performance engines (180hp/131kW and 205hp/150kW). Thanks to its combination of advanced driving pleasure at an affordable price with a three year/150,000km warranty, Renault Laguna GT stands out as an innovative offer in the European sports saloon market.
Five months after its release, almost 42,000 Renault Lagunas have already been sold in 30 countries. In western Europe, 51,125 orders have already been taken, the majority of which have specified diesel power (87 per cent) and top-end equipment levels (Dynamique: 43 per cent; Privilθge: 19 per cent; Initiale: 12 per cent). Since the start of 2008, Renault Laguna's market share has grown constantly, fuelled by the Estate version (already six per cent of the D segment in western Europe as of end-February). Despite the massive wave of model renewals recently, this segment continues to erode at an average yearly rate of six per cent. The GT version of Renault Laguna, which is powered by two bespoke engines, places the accent on enjoyment and efficiency to deliver outstanding yet reassuring and pleasurable onroad performance, an experience to which its even more precise and responsive chassis and accomplished four-wheel steering technology amply contributes. With quality an overriding concern throughout its design and production, Renault Laguna ensures a reassuring ride for all occupants thanks to its class-topping active and passive safety and a raft of practical features. Meanwhile, Renault Laguna GT's crisp, distinctive styling belies its top-end positioning within the Laguna range in terms of technology and powerplants. Available in saloon and estate form with a three-year or 150,000km warranty, Renault Laguna GT goes on sale in France from 12th April, 2008, and then gradually across the majority of Europe by the (northern) summer of 2008.
Four-wheel steering for an exceptional ride
The Active Drive chassis with four-wheel steering brings many benefits, starting with improved manoeuvrability, extremely rigorous dynamic response, and unequalled steering precision which gives the driver truly intuitive control over the cornering line, to attain new heights in driveability and active safety. The steering is immediately reassuring and agreeable, even at low speeds. In town and on winding roads, the car is easy to drive: manoeuvrable and precise. Advanced roll control, with specific settings and reinforced seat support, gives the impression that Renault Laguna GT corners flat, without leaning into the bend. The driver is pleasantly surprised by the lack of transient dynamic phenomena when cornering, and by the extreme precision achieved by very small steering wheel angles. The Active Drive chassis with four-wheel steering also excels in active safety, both under difficult braking conditions (with good control over asymmetrical grip, and ESP matched to sporty driving styles), and during avoidance manoeuvres at speed ('elk' test).
Impressive low-speed manoeuvrability
The Active Drive chassis with four-wheel steering makes Renault Laguna GT exceptionally easy to handle in town and superbly agile on winding roads. At speeds of less than 60 km/h, the rear wheels turn in the opposite direction to the front wheels, up to an angle of 3.5°. This brings two advantages: a smaller turning circle, for easy manoeuvring; and smaller steering wheel angles thanks to the more direct, specially calibrated steering. With four-wheel steering on the Active Drive chassis, Renault Laguna GT has a 10 per cent smaller turning circle than with two-wheel steering: 10.80 metres (the same as Clio!) with 18-inch tyres, instead of 12.05 m. The greater the rear-wheel steering angle, the smaller the turning circle. Enhanced manoeuvrability is especially remarkable in tight parking situations and along narrow city streets.
With front wheels and rear wheels turning in opposite directions, the car effectively pivots, which means smaller steering angles are needed for the same turning effect. Whereas it takes a 16° steering wheel angle to produce a 1° turn in the front wheels on New Laguna, it takes just 13.5° with the Active Drive chassis. And this drops to 12° when the rear wheels are turned at the maximum 3.5° angle in the opposite direction to the front wheels. Because steering is more direct, with less need for wide steering wheel angles, the impression of manoeuvrability and agility is greatly enhanced. For any given bend profile, the driver will need less action on the steering wheel. This makes for more effective avoidance, with the car seeming to weave effortlessly around obstacles.
Ultra-precise steering control
From 60 km/h, the emphasis is on steering precision. The rear wheels turn simultaneously in the same direction as the front wheels, to enhance stability, almost as if the car were running on rails. The Active Drive system with four-wheel steering counters the centrifugal force that tends to push the rear end outwards round bends, and thus raises the safe cornering speed. The rear axle is set on the ideal trajectory, with a rear-wheel angle of less than 2° in most situations, for stability and efficacy. The Active Drive chassis with four-wheel steering enhances dynamic handling, with sound, reassuring response for outstanding driving pleasure.
Unparalleled active safety
The Active Drive chassis with four-wheel steering also improves safety for heightened reassurance during avoidance manoeuvres. In an emergency situation, the rear-wheel angle can rise to 3.5°. Cut-in of the ESC (Electronic Stability Control) system, specially configured for a sporty driving style, is delayed, so that the manoeuvre can be performed both safely and more swiftly. ESC only switches in when necessary, and is applied gradually because it is synchronised with the rear-wheel turn action. Via the ESC/ABS unit, the 4WS control unit also detects asymmetrical braking situations, adapting the rear-wheel turn angle automatically to keep the car stable with no driver action required. This helps the driver keep control during critical situations, and ensures uninterrupted peace of mind during everyday driving conditions.
Dynamic control logic
Developed jointly by Renault and Renault Sport Technologies, the Active Drive chassis with four wheel steering implements electronic control of vehicle dynamics. A sensor on the steering column sends steering wheel angle information via the CAN network to the 4WD control unit, located behind the rear axle. The 4WD control unit also inputs vehicle speed from the ESP/ABS unit. And it tracks steering wheel angle information to detect sharp steering wheel movements symptomatic of a sports driving style or avoidance situation. All these parameters are analysed to determine the required rear-wheel turn angle, which is implemented by means of an electric actuator on the rear axle. Dynamic vehicle behaviour is precisely modelled to set the ideal vehicle trajectory at each instant, on the basis of the drivers input and the actual situation of the vehicle. The controller and electric actuator are supplied by Aisin, a Japanese equipment supplier reputed for its experience in four-wheel steering systems.
The diesel version of Renault Laguna GT is powered by a 2.0 dCi engine, best-in-class for performance, driveability and acoustics. In this implementation, it yields exceptional peak power of 180 hp/131 kW at 3,750 rpm. Peak torque of 400 Nm is available from 2,000 rpm, for prompt, consistent, sustained build-up through to 5,000 rpm. A reduced-inertia variable-nozzle turbocharger enhances dynamic response at low revs to achieve superlative performance: 29.6 seconds for the 1,000 m standing start and 0 to 100 km/h in 8.5 seconds. This new unit is fitted with a particulate filter and EGR valve with enhanced cooling, which makes intense driving pleasure perfectly consistent with environmental protection: mixed-cycle fuel consumption is just 6.5 litres/100km, which translates into CO2 emissions of just 172 g/km. With its ultra-fast glow plugs, the 180 hp/131 kW 2.0 dCi unit roars into action instantly when the Start button is pressed, even in conditions of extreme cold (down to -23°C).
The petrol version of Renault Laguna GT is powered by a sports version (205hp/150kW at 5,000 rpm and 300 Nm from 3,000 rpm) of the two-litre 16-valve unit, derived from Renault Sport technology as featured on Mιgane Renault Sport, and specifically reworked for Renault Laguna GT, to yield the best in performance, handling and intense driving pleasure. It is superbly versatile, combining velvet smoothness with astonishingly crisp response, ideal for sports usage. Design features such as the special air-intake system and twin-scroll turbo ensure the revcounter leaps forward at the slightest touch of the throttle. Renault Laguna GT 2.0T accelerates from 0 to 100 km/h in 7.8 seconds and takes 28s to cover 1,000 metres from standstill. Yet fuel consumption is a very reasonable 8.2 litres/100 km, which makes for CO2 emissions of just 194 g/km.
Distinctive GT styling
With its distinctive streamlined profile, Renault Laguna GT expresses an elegance that goes much further than sporting aptitude alone. The long plunging bonnet terminates in a highly assertive front-end with a radiator grille characteristic of the most powerful Renaults. Purposeful looking lateral air-intakes suggest an insatiable appetite for the open road, corroborated by the wise gaze of the headlamps against the neat black background. Renault Laguna GT is fitted with generously sized 225/45 18-inch special high performance Bridgestone Potenza tyres, a Formula One spin-off, mounted on special Celsium wheels. The highly efficacious braking system uses 320 mm diameter discs at the front and 300 mm discs at the rear. Aerodynamic sills reflect the promise of the Active Drive chassis extend from the front of the car to the characteristic straight-section twin tailpipe at the rear. Sports tourer attributes run through to every last detail, such as the gloss black wing mirrors and smoked rear lamp units.
As well as appearing on the outside centre pillar, the exclusive GT logo is also embossed on the light grey alcantara of the front seatbacks. As on all Renault Laguna models, the interior design exudes a most impressive sense of comfort and quality, in all seats. Sports design details abound, highlighting the exclusive capacities of the GT version: special three-spoke leather sports steering wheel with grey stitching, cross-drilled aluminium pedal, sports gearshift lever knob, dark charcoal Riviera leather upholstery with reinforced lateral support. Extreme attention has been paid to materials and finish, true to the cars unwavering commitment to pure motoring pleasure.
Equipments and technology
The Renault Laguna GT range starts with the Dynamique equipment level and features a long list of top-end equipment selected to favour travelling comfort, including a three-mode (Soft/Auto/Fast) dual-zone automatic climate control system complete with toxicity sensor and automatic air recycling. Driving comfort is enhanced by the availability of parking brake assist, cruise control with speed limiter and automatic headlamp and wiper activation, while acoustic comfort was dialled into the model from a very early phase in its development thanks to features that have made Renault Laguna a benchmark in this area, too. Nothing has been left to chance on the active and passive safety fronts either. Renault Laguna and the GT version particularly excel in terms of their active safety performance as demonstrated by the latest EuroNCAP test results. Its principal innovation concerns improved side impact protection thanks to a twin impact sensor system and new generation double thorax/groin airbags.
The affordable overall equipment and performance package of this flagship version sets it apart on the sports saloon marketplace and ensures the ultimate in reassuring driving pleasure.
Advanced technology for an unforgettable ride
Four-wheel steering systems of the 1980s were essentially mechanical, with the front and rear wheels linked and pre-determined angles aimed at making up for shortcomings in the vehicle's handling (e.g. a tendency to understeer). Such systems were gradually superseded by the advent of ESP (electronic stability programme). Meanwhile, towards the end of the 1990s, carmakers like Nissan were beginning to develop solutions based on electrically- and even hydraulically-operated activators with a view to taking the dynamic performance of their vehicles forward. Electronic control of the rear wheels has enabled handling to be fine-tuned even further, notably in the case of rear-wheel drive vehicles.
The Active Drive system builds on this approach by ensuring a more dynamic and more reactive response to make the absolute most of the inherent qualities of Renault Laguna GT's remarkable chassis and consequently deliver even greater driving enjoyment. In addition to the complex modelling of the vehicle's handling, real-time response to the driver's instructions (every 10 ms) and its ability to adapt to different conditions, new Laguna GT's Active Drive four-wheel steering system means that active safety systems are only required as a very last resort, which means drivers benefit from more efficient and even more reassuring reactions when faced with an unexpected driving situation.
LAGUNA GT EQUIPMENT
PRINCIPAL EQUIPMENT AND OPTIONS
SPECIFIC TO ESTATE GT
The Renault Laguna is coming to Australia later this year. Model selection and specifications of Australian models will be announced in due course.
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