In the SUV world, the new Mercedes-Benz GL-Class is setting new standards in comfort, dynamics, safety, elegance and efficiency and with this spectrum it is regarded as the S-Class among off-road vehicles. This premium SUV is able to demonstrate its exceptional capabilities in everyday situations with dense city traffic, over very winding roads or on well-built motorways as well as way off the beaten track. Here the multi-talent's qualities are even more evident. Whether driving over tracks with potholes, continually altering road surfaces or dusty natural trails interspersed with off-road sections - the superior comfort of the seven-seater's ride as well as its outstanding power and confident performance are really convincing even when the going gets really tough.
Relaxed - and that means safe - driving both on-road and off-road - is one of the great strengths of the new GL-Class. Especially its NVH qualities (noise, vibration, harshness) are very convincing and are on a par with those of the S-Class. The high standards of comfort are derived from the combined result of a very rigid bodyshell, a perfected drivetrain, improved chassis and superb aeroacoustic finishing as well as the intelligent use of new-style insulation materials. At the same time, the Mercedes-Benz GL-Class retains its traditional advantages of being extremely responsive with outstanding off-road expertise.
Included in the standard package are the fully load-bearing air suspension system AIRMATIC with its adaptive shock-absorbing system (ADS) as well as a load recognition feature. In comparison with the previous model, the AIRMATIC ADS provides outstanding comfort with greatly improved handling, roadholding and driving dynamics. For example, both the standard Crosswind Assist and load recognition feature are able to compensate for very varying driving conditions. The optional active tilting stabiliser ACTIVE CURVE SYSTEM uses its active lateral stabilisers for the front and rear axles to reduce the roll angle when driving round bends, thus providing a greatly improved response and more fun behind the wheel. At the same time, the system makes for better handling. An improved ride and increased scope when driving off-road by actively decoupling the stabilisers are among the other advantages of the ACTIVE CURVE SYSTEM.
Quick-change artist: the ON&OFFROAD package
The GL is really well-equipped for going on tours off the beaten track. The standard package also includes the permanent four-wheel drive 4MATIC, a driving-off assistant, the Downhill Speed Regulation DSR and a special program for off-road driving. The ON&OFFROAD package of the new Mercedes-Benz GL-Class with its six driving programs has greatly improved the vehicle dynamics and driving safety so that the most suitable drive control for extremely varying driving conditions both on the road and going cross-country is always available. From the "hardware" point of view, the ON&OFFROAD package comprises an underrun protection for the engine, fibre-reinforced underfloor panelling, a two-stage power transmission with reduction gears, a longitudinal differential lock and extended AIRMATIC functions allowing a maximum ground clearance of 306 mm and fording depth of 600 mm.
Better visibility, more safety, greater comfort
When it is dark or visibility is poor, the Bi-Xenon headlamps with Intelligent Light System and new off-road light, adaptive Main Beam Assist or adaptive Night View Assist P lus provide sufficient visibility. The optional 360Â° camera has four cameras at front and rear as well as in the housing of the exterior mirrors- and is especially helpful in big city jungles. From the picture information received, the system calculates a bird's eye view of the vehicle and its surrounding area and then relays it together with other views to the large COMAND display.
New Assist systems: The best support for the driver
Improved driving and stress-reduced safety for the new Mercedes-Benz GL-Class is provided in particular by its numerous assistant systems. In addition to the handling control systems ESPÂ®, ASR, ABS and the danger-alert PRE-SAFEÂ® safety concept, for the first time the standard version of the GL is also fitted with the collision warner COLLISION PREVENTION ASSIST and the drowsiness detector ATTENTION ASSIST. Functions such as load recognition or STEER CONTROL reduce the strain on the driver in critical borderline driving situations as for instance by supporting the driver with a steering momentum on the steering wheel if the vehicle is oversteering. One innovation and highlight in the new GL is the standard Crosswind Assist which supports the driver with deliberate braking action when there are strong crosswinds, thus increasing the feeling of safety. Also available to optimise the safety of the vehicle are optional systems such as distance control DISTRONIC PLUS, braking assistant BAS PLUS or the PRE-SAFEÂ® brake with its autonomous braking function in certain dangerous situations that have not been recognised by the driver . Easy parking is guaranteed with the Active-Park assistant. The system is able to detect suitable parking spaces and steers the GL automatically into the best possible position for parking.
Mercedes-Benz GL-Class drive systems: Up to 20 per cent reduction in fuel consumption
Both the BlueTEC engine for the GL 350 BlueTEC 4MATIC and the GL 500 4MATIC BlueEFFICIENCY with supercharged direct injection BlueDIRECT petrol engine give extremely efficient and outstanding performances. The fuel consumption of the GL 350 BlueTEC 4MATIC is 7.4 litres diesel per hundred kilometres which is about 20 per cent less than its predecessor, and at the same time it undercuts the future EU 6 emission standards. The fuel consumption of the 320 kW (435 hp) strong petrol engine GL 500 4MATIC BlueEFFICIENCY has been reduced by 18 per cent. With the change of models the GL range is being enriched by an AMG version for the very first time. In the high-performance SUV GL63 AMG, the AMG 5.5 litre V8 Biturbo engine provides a top performance of 410 kW (557 hp) and maximum torque of 760 Nm. The GL63 AMG accelerates from zero to 100 km/h in 4.9 seconds; it has a top speed of 250 km/h (limited electronically). The NEFZ fuel consumption is 12.3 litres per 100 kilometres (288 g CO2/km).
In addition to the state-of-the-art engine technology, an extensive BlueEFFICIENCY package supports the outstandingly economic fuel consumption. This includes the new seven-gear automatic transmission 7G-TRONIC PLUS as well as the standard ECO stop-start function. The intelligent generator management, electric power steering and reduced rolling resistance of the tyres also have a fuel-saving effect.
In comparison with its predecessor (GL 350 BlueTEC 4MATIC), the weight of the new GL-Class has been reduced by 90 kg due to the extensive use of lightweight construction methods. These include the use of light but durable aluminium alloys for the bonnet and wings. The front and rear suspension links are also made of light alloys. This pays twice over: On the one hand the lower weight reduces energy requirements, and on the other hand the vehicle provides a more comfortable ride due to its lower unsprung mass. Other weight reductions are the new acoustic windscreen, the magnesium cross beam of the dashboard, the BlueTEC system with SCR technology or components such as the new electric power steering, the electric parking brake or a plastic engine support.
The interior of the GL: First Class for seven people
In addition to its extremely comfortable ride with excellent dynamic driving features both on the road as well as over very rough terrain, the Mercedes-Benz GL-Class spoils its passengers with an interior which comes up to the first class standards of a luxurious saloon. Up to seven passengers are able to enjoy the outstanding seating. The elegant interior decoration is dynamic and full of vigour with high-quality materials and great attention has been paid to details; the generous space arrangement has a perfect ergonomic design - the interior of the GL-Class conveys the feeling of well-being typical for the Mercedes-Benz brand. Extensive trim elements in various kinds of wood or in aluminium, controls in silver-chrome and upholstery in permeable ARTICO man-made leather material with decorative topstitching on the seams in a contrasting colour underline the overall high-quality impression.
The 2-3-2 seating arrangement provides a generous amount of space. In comparison with its predecessor, the passengers have been given a great deal more elbow, shoulder and headroom in all three rows of seats. As a standard feature, the third row of seats can be folded down and up electrically. Another innovation is the EASY-ENTRY system for accessing the third row of seats from both sides - also if required with optional electric controls.
As another first for a series model SUV, Mercedes-Benz is offering an optional sound system for the Mercedes-Benz GL-Class from the well-known manufacturers of music systems Bang & Olufsen. The Bang & Olufsen BeoSound AMG High-End Surround-Sound System with a total output of 1200 W and 14 high-end loudspeakers transforms the interior of the car into a concert hall with breathtaking acoustic.
Mercedes-Benz is the first car manufacturer to evaluate and assess the role of aeroacoustic which provides the decisive parameters for a comfortable ride especially when travelling at higher speeds. As a result, the psychoacoustic characteristics of SUV models like the GL-Class have been considerably improved. Here not only the high frequency wind noises were rated, but also the low frequencies - especially those concerning the comprehensibility and audibility of spoken language. A comparison with the S-Class proves just how successful the GL engineers were: the objective and subjective impression of noise lies at the same level for both vehicles. Because of its typical SUV design, however, it took a great deal more effort to achieve these top results with the GL than with a luxury saloon. Furthermore, the full-size SUV provides excellent acoustic for seven passengers sitting in three rows - and that under even the most unfavourable conditions as the off-roader can be used in a much wider variety of situations than the saloon including travelling in remote areas far away from sealed roads.
First Class design
Right at first sight, the Mercedes-Benz GL-Class can be recognised as a typical member of the Mercedes-Benz SUV family. The new interpretation of the first generation is very impressive with its pronounced dynamic strength and sporting elegance. At the front, the design is dominated by the GL's typically upright radiator grille with its central star and the clear, high-quality design of the headlamps - the new Mercedes-Benz LED signature. In particular, the standard Intelligent Light System headlamps on the GL 500 4MATIC BlueEFFICIENCY give a high-quality, exclusive and innovative impression. The difference lies in a light wave conductor for the position lights, LED technology indicators and the practical Night View Assist PLUS which is available as an option. The daytime running lamps, also in LED technology are integrated in a chrome clasp in the bumper and underneath the radiator grille the large underbody panel in chrome look rounds off the self-confident appearance of the front. The well-balanced proportions of the side view (length 5120 mm, height 1850 mm) and the long wheelbase (3075 mm) underline the vehicle's on-road emphasis, but at the same time the short body overhang at front and rear together with the vehicle's great ground clearance point to its suitability for off-road travel. The rear with its two-piece LED rear lamps using light wave conductor technology, a large roof spoiler, the bumper with its modern "wing design" and the large chromed area of the underbody panel complete its appearance as befits the social status of this luxurious full-size SUV. For the first time there is an extensive AMG exterior sport package available for those GL customers who find it increasingly important for their vehicle to have a sporting and dynamic appearance.
Passive safety: All-round protection for all passengers
Maximum protection potential is provided by the passive protection systems for passengers in conjunction with the "electronic crumple zone" provided by the assistant systems and the intelligent body construction. Adaptable two-stage airbags for the driver and front passenger, knee bags for the driver, sidebags for the driver and front passenger (combined thorax/pelvis bags) and window bags for all three rows of seats are part of the standard package. The integration of the optional thorax bags in the backrest of the tilt-adjustable folding seat in the middle row of seats allows the airbag to be in the best possible position regardless of the position of the backrest. Furthermore, there are 3-point seat belts for all seven passenger seats on board. Also part of the standard package are the pyrotechnical inertia reel tensioners and constant belt force-limiters as well as electrically reversible belt reel-in tensioners at the front, inertia reel tensioners and single stage force-limiters on the outer seats of the middle bench seat as well as on the rear single seats. The GL-Class also provides the best-possible protection with regard to weaker road users such as pedestrians and cyclists. Among other things, the standard active bonnet comes into action.
Body design and interior: Dynamic appearance, striking interior
At the very first glance, the Mercedes-Benz GL-Class can be recognised as a typical member of the Mercedes-Benz SUV family. The new interpretation of the first generation is very impressive with its pronounced dynamic strength and sporting elegance. At the front, the design is dominated by the GL's typically upright radiator grille with its central star and the clear, high-quality design of the headlamps with their LED lights. In particular, the standard Intelligent Light System headlamps on the GL 500 4MATIC BlueEFFICIENCY give a high-quality, exclusive and innovative impression. The difference lies in a light wave conductor for the position lights, LED technology indicators and the practical Night View Assist PLUS which is available as an option. The daytime running lamps, also in LED-technology are integrated in a chrome clasp in the bumper and underneath the radiator grille the large underbody panel in chrome look rounds off the self-confident appearance of the front.
The well-balanced proportions of the side view (length 5120 mm, height 1850 mm) and the long wheelbase (3075 mm) underline the vehicle's on-road emphasis, but at the same time the short body overhang at front and rear together with the vehicle's great ground clearance point to its suitability for off-road travel. The high upper edge of the body typical for SUVs with its high-quality chrome trim, the dynamically rising line emphasising its character and the chrome casing round the windows underline its superior appearance. In the standard version the GL stands on attractive 18 inch alloy wheels designed with 10 spokes, as an option wheels up to 53.3 cm (21 inch) are available. The rear with its two-piece LED rear lamps using light wave conductor technology, a large roof spoiler and the bumper with its modern "wing design" with the large chromed area of the underbody panel completes its appearance as befits the social status of this luxurious full-size SUV. In the petrol-driven models, chromed ends to the exhaust pipes complete the standard package.
For the first time there is an extensive AMG exterior sport package available for those GL customers who find it increasingly important for their vehicle to have a sporting and dynamic appearance. In addition to the front and rear aprons typical for AMG, the package also provides special side flaps which are clamped over the 53.3 cm (21 inch) AMG alloy wheels with their five double-spokes design. Aluminium running boards with courtesy lights are just as much part of the package as perforated brake discs and brake calliper covers with Mercedes-Benz lettering.
Inner values: The GL-Class offers First Class automotive quality
Elegant and dynamic interior decoration, high-quality materials and great attention paid to details, perfect ergonomics and a generous amount of space - the interior of the GL-Class conveys the feeling of well-being typical for the Mercedes-Benz brand. Extensive trim elements in various kinds of wood or in aluminium, controls in silver-chrome and upholstery in perforated ARTICO man-made leather material with decorative topstitching on the seams in a contrasting colour all go to underline the overall impression of high-quality. The 2-3-2 seating arrangement provides plenty of room for seven passengers.
As a standard feature, the luggage compartment can be enlarged by folding down the third row of seats electrically - either from the two rear doors or from the luggage compartment - and putting them up when required just by pressing a button. Another innovation is the EASY-ENTRY system on both sides for the second row of seats - also with optional electric controls - to give better access to the third row of seats. The middle row of seats has a great variety of adjustments, making the use of interior space much more variable as for instance with a "cargo-position" to enlarge the size the luggage compartment. It then provides a volume of 680 to 2300 litres which is greater than the high capacity provided by its predecessor.
In comparison with its predecessor, the passengers have a great deal more elbow and headroom at their disposal in all three rows of seats. For all the other classic standards for a comfortable ride such as the distance between the rows or the width allowed for shoulders, its predecessor already was the best in its class.
These measurements clearly show the degree of comfort: The space provided by the new Mercedes-Benz GL-Class is even more generous than before. In particular in the third row of seats the available space is also outstanding. The easy access is also very impressive. Passengers can get into the interior easily due to the wide opening angle of the doors at front and rear and the high edge of the roof which is typical for SUV vehicles. Loading the luggage compartment is also simple due to the height of 1.95 m under the open tailgate.
Multicontour seats with seat cooling using reversing seat fans and COMAND-adjustment
The optional multicontour leather seats for driver and front passenger also have - as an additional option - a reversing seat ventilation which considerably improves seating comfort in summer especially when the interior of a vehicle overheats after being parked in the blazing sun. Four mini-fans pro seat are fitted in the driver and front passenger's seat cushions and backrests so that they suck air out of the interior of the vehicle. This is then pumped into the upper layer of the seat cushion and distributed evenly under the leather cover. The defined airflow passes through the perforated leather cover and draws off any moisture left on the passengers' body or clothing. The response time is much more efficient with reversing fans. In the first few minutes after the seat ventilation has been activated, the fans suck up the hot and humid air through the perforations and increase the effect of the air-conditioning - in comparison with the blowing function, the surfaces of the seats cool down appreciably faster during the first 30 seconds.
As usual in Mercedes-Benz vehicles, basic seat adjustments for legroom and backrest angle can be made using the buttons in the interior door panel showing a stylised seat which is easy for both driver and front passenger to use. What are new, however, are the fine adjustments of the multi-contour functions such as the depth of the seat cushion, the side supports of the seat and backrest or the lumbar support. These adjustments can now be made easily and clearly using the COMAND controller on the centre console. After selecting the appropriate menu using the button on the centre console, the graphic on the COMAND display shows a multi-contour seat and the areas selected for adjustment are visualised in colour. Compared to the keyboards next to the seats used up to now, this procedure clearly simplifies the adjustment procedure. The massage function is also new: Both driver and front passenger can have the luxury of a back massage individualised according to intensity and speed.
Always in view, everything under control: Dashboard and centre console
The dashboard covered in ARTICO leather continues the optical emphasis on width in the interior of the vehicle. The two modern round instrument clusters are clearly designed and easy to read, and situated between the instrument hoods the large 12.2 cm (4.8 in) photo-realistic colour display has a very appealing high-quality charm. Next to them, the centre of the dashboard is dominated by the large main COMAND colour screen. The operating and display concept has undisputed advantages for the user: Infotainment, navigation and communication can all be used easily and very simply with the COMAND controller positioned on the centre console in a metal casing. The multifunctional steering wheel covered in nappa leather is standard and fitted with gear shift paddles and 12 buttons with various functions.
Below the central armrest with its integrated pad for the ball of the thumb there is a large stowage tray and in front of it are the controller and various switches, for instance for the ON&OFFROAD package, air suspension AIRMATIC or the COMAND system. Also integrated here are the two optional heatable and coolable cup holders which can be covered with a high-quality wooden blind. The standard USB interfaces and the AUX-IN jack are also to be found on the central armrest. The decorative elements found on the dashboard are also reflected in the striking decorative seams of the door linings. As an option, the designo Exclusive-Package is available: This includes top quality designo nappa leather, extremely stylish decorative seams and exclusive diamond-patterned quilting on the seats and door linings.
Bang & Olufsen BeoSound AMG High-End Sound System
As another first for a series model SUV, Mercedes-Benz is offering an optional sound system for the GL-Class from the well-known Danish manufacturers of high-fidelity systems Bang & Olufsen. The Bang & Olufsen BeoSound AMG High-End Sound System with 14 high-end loudspeakers, a total output of 1200 W and B&O ICE power Class D Technology enhances the listening pleasure in comparison with other known sound systems and transforms the interior of the car into a concert hall with breathtaking acoustic. The equipment allows the user to select either the high-end studio sound "Reference" or wide-reaching spatial surround sound. Furthermore, the sound fields can be directed exactly toward the driver's and front passenger's seats or centrally. All the functions are easy to operate using a special Bang & Olufsen menu in the COMAND infotainment system.
As the driver and front passenger in a car practically never find themselves in the ideal position between the speakers, the distance between each of the loudspeakers and the passenger's ear is inevitably different and also this involves a different time lapse. This means, for instance, that in a left-hand drive vehicle the sound waves take longer to travel from the right high-frequency tweeter to the right ear of the driver as from the left high-frequency tweeter to the left ear. This delay due to physical reasons is compensated by the digital sound processor (DSP) - and even individually for each of the fourteen loudspeakers. Special software has been developed to provide very precise sound tuning and this is stored in the DSP for every individual seat. This means that passengers are able to select the required seats in the Bang & Olufsen sound menu. The virtual sound stage is perceived as being directly in front of the passengers and thus corresponds to the natural human listening habits when enjoying music. Every type of instrument - guitar, strings, wind section, piano or synthesisers - is convincingly natural, fresh and dynamic. The same is true for the various types of voice: Singing from both men and women sounds just as authentic as pure voice reproduction, for instance in news programmes. It also does not matter what the personal musical tastes of the passengers are or what the source is: The Bang & Olufsen BeoSound AMG High-End Sound System reproduces every type of music perfectly from classical music to blues, jazz, pop, rock and electro to hip-hop, irrespective of whether it is from a CD, DVD, TV/Video, mp3 player or the radio.
The Bang & Olufsen ICE PowerÂ® amplifier (ICE = Intelligent, Compact, Efficient) serves as the perfect addition to the 14 loudspeakers and the DSP. The amplifier converts about 93 per cent of the input energy into performance and is closely linked to the DSP.
A very important contribution to the outstanding listening pleasure is due to the dynamic compensation for driving noises during very varying traffic and environmental situations: The microphone integrated in the overhead control panel constantly supplies data on the current noise levels within the car and their influence depending on the frequency. The digital sound processor analyses all the wavebands and raises the volume as required individually for each loudspeaker and for the varying frequencies. In this way, very varying sources of noise can be compensated. One extreme example: If the GL has to stop at traffic lights right next to road works using an asphalt cutter, the DSP modulates the system so that the noise input is compensated for as far as the limits of physical laws allow. Compensation is also made for "normal" noises such as those from tyres, wind, engine, gears or even rain.
One optical hint pointing to the remarkable performance of the Bang & Olufsen BeoSound AMG High-End Sound System are the striking illuminated oval tweeters with "Acoustic Lens Technology" in the mirror triangle as well as the impressive Bang & Olufsen "Silver Shadow" aluminium covers for the door loudspeakers.
Calm despite the storm: The new GL is the quietest vehicle in the whole of the SUV world
As the very first car manufacturer, Mercedes-Benz has researched the psychoacoustic qualities of vehicles to find out more about aeroacoustic.Here both high frequencies of wind noise as well as the contribution of low frequencies, and in particular the audibility of voices was examined and optimised. During their research, the engineers devoted themselves intensively to the airflow around the vehicle body, the sealing systems on windows and doors as well as the body-in-white. The main focus of such work is not just on the absolute sonic pressure (dB (A)). The aim is rather to generate acoustic which is as homogenous and harmonious as possible, where neither definite frequency ranges nor individual vehicle components or sectors are dominant, as from a speed of about 120 km/h the wind noises are the dominant acoustic quantity. Tyre or engine noises are relegated to the background. Individual aeroacoustic measures taken:
Just how successful the aeroacoustic engineers were in tuning the GL "resonance box" can be seen by a comparison with the S-Class: The objective and subjective impression of noise lies at the same pleasant level for both vehicles. However, achieving these top results with the GL requires a great deal more effort than with the luxury saloon. On the one hand because of its typical SUV shape and the large front surface.
On the other hand, the full-size SUV provides excellent acoustic for seven passengers sitting in three rows even under unfavourable conditions as the off-road vehicle can be used in a much wider variety of situations than a saloon - also including travelling in remote areas far away from sealed roads.
Clear proof of the importance of aeroacoustic for Mercedes-Benz is shown by the development of new testing plants. Normal wind tunnels have reached their physical limits as far as the further optimisation of aeroacoustic is concerned as here the interference from the testing equipment is superimposed on the test results. To put it briefly: Mercedes-Benz vehicles like the GL-Class now run so quietly that innovative developments using the present testing equipment would require a great deal of effort to achieve. That is why at the moment a revolutionary interference-optimised wind tunnel is being built at the Mercedes-Benz Technology Centre (MTC) in Sindelfingen. The testing installation will be opened in 2013 and is a guarantee for future automotive development that the company will continue to retain its lead in aeroacoustic over its competitors.
Quality of ride and vehicle dynamics: Superior performance on and off-road
Relaxed, comfortable and superior driving including a great deal of fun driving in all kinds of situations - these are the great strengths of the Mercedes-Benz GL-Class. Compared with its predecessor, the new model is a winner with even better response and dynamic road handling. The nimble way this full-size SUV with permanent four-wheel drive goes about its business is otherwise only to be found in much more compact and sporty off-roaders. The fact that the quality of the riding comfort could be increased to such an outstanding level despite all the GLs dynamic handling is one of the special achievements of the development team. Especially the NVH qualities (noise, vibration, harshness) of all the GL models are very convincing and are on a par with those of the S-Class. The high standards of comfort are derived from the combined result of a very rigid bodyshell, a perfected drivetrain, improved chassis and superb aeroacoustic finishing as well as the intelligent use of new-style insulation materials.
Floating along: Air suspension AIRMATIC ADS
The fully load-bearing air suspension system AIRMATIC with its adaptive shock-absorbing system (ADS) provides a comfortable basic springing with a low inherent frequency, although the full length of spring travel is also available when the vehicle is fully loaded. When driving on the road it provides outstanding comfort and clearly improved handling. AIRMATIC compensates various loads and driving conditions and at the same time acts as a level control. When driving way off the beaten track, the air suspension increases off-road mobility with extra riding height. The lifting or lowering of the body can be activated at any time when the engine is running and can either be done automatically or as the driver requires using the control buttons on the centre console. The system is speed-dependent and lowers the body at high speeds to minimise aerodynamic resistance while at the same time increasing driving stability. The main features of the air suspension are:
The adaptive shock-absorbing system ADS is a fully automatic, electronically controlled system which adjusts the shock-absorbers on each wheel as required. Unlike a passive system with constant settings, the vehicle is stabilised equally in all driving situations which improves handling and leads to a perceptible calming of the body. If the response of the body movement is low, the GL-Class drives at level 1. When the speed of the body movement exceeds a certain level, the system goes into the so-called skyhook algorithm and switches as needed back and forth between the second and third shock-absorbing levels using its fast magnet valves in order to compensate the tilting and pitching motion of the body. In more dynamic driving situations, level 4 is activated and in the sport mode only level 4 is used. The regulation of each individual wheel takes place almost immediately. Depending on the command received, the valves can adjust to one of the characteristic curves mentioned in less than 0.05 seconds.
The specific driving situation is recognised by a steering angle sensor, four turning angle sensors and the driving speed from the ESPÂ® signal and brake pedal switch. With the aid of these signals, the control unit calculates the current shock-absorbing strength required and activates the appropriate characteristic curve for the shock absorbing system. Via a switch, the driver can preselect the required performance graph Sport or Comfort manually.
In the new GL-Class an electromechanically supported Direct-Steer system works with a variable steering ratio which becomes perceptibly more direct when the steering angle has an upwards trend. This gives the driver better feedback from the road so that he does not need to work so hard at steering. On the other hand, this also improves the handling and response of the vehicle making it more fun to drive both on very winding roads and in city traffic. In addition, electric steering gives speed-dependent steering support and thus provides clearly improved steering comfort over the whole speed range.
Greater vehicle dynamics with load sensor system - as standard
A patent is pending for the new load sensors developed by research engineers to improve driving dynamics even further. The system is able to recognise various vehicle loads carried by the GL and with the data received it is able to alter the regulating thresholds of the ESPÂ® accordingly. Up to now, the ESPÂ® always presupposed a vehicle loaded to the maximum with a complete roof load. The new load sensor system now intervenes only when required by the actual load carried and has a positive effect on vehicle dynamics.
An effective sensor system within the air suspension system AIRMATIC recognises the load situation at the time: The load carried by the vehicle leads to alterations in the axle loads of the front and rear axles. The difference in pressure between the front and the rear axle serves here as a reliable measurement for moving the height of the centre of gravity as the wheel pressures determined by the AIRMATIC pressure sensors are proportional to the wheel loads. The adjustment of the regulating threshold is effected according to the wheel pressures determined; the ESPÂ® interventions are carried out more sensitively and according to the actual load carried.
The ESPÂ® adaptation takes place after driving a short distance. When the vehicle starts driving, the load sensor system presumes that the vehicle is fully occupied with a full load. This means that safest driving situation possible is always guaranteed.
New driving dynamics system ACTIVE CURVE SYSTEM
The optional active tilting stabiliser ACTIVE CURVE SYSTEM can be combined either with the air-suspension system AIRMATIC with the adaptive shock-absorbing system (ADS) or with the ON&OFFROAD package. The system uses its active lateral stabilisers on the front and rear axles to regulate them automatically depending on the lateral acceleration, speed and position of the ADS Comfort/Sport switch. The ACTIVE CURVE SYSTEM compensates the roll angle of the body when driving round bends, thus providing a greatly improved vehicle response and more driving pleasure. At the same time, the system improves handling and safety when driving at high speeds. An improved ride both driving round bends as well as on straight roads and increased scope when driving off-road are among the other advantages of the ACTIVE CURVE SYSTEM. Individually, the control strategies are:
Improved vehicle dynamics achieved when driving round bends as the starting torque and torque angle of the stabilisers are actively influenced. Furthermore, the starting torque of the stabilisers remains constant even when exposed to one-sided activation, for instance when driving over a pothole or round the outer periphery of a curve. The varying regulation of the front and rear axles distributes the roll moment variably so that under/oversteering characteristics are adjusted to the individual driving situation. When driving on country roads the handling is regulated so that it is particularly responsive and on motorways so that it is especially stable.
In extreme off-road situations at low speeds, both of the lateral stabilisers are decoupled to allow an improved degree of axle articulation.
A belt-driven hydraulic pump and an oil container in the engine compartment together with one valve block each and active stabilisers on both front and rear axles are among the important components of the active roll stabilisers. In comparison with a passive stabiliser, the active stabilisers are divided in the middle and connected to each other by hydraulic actuators. Pressure sensors and a lateral acceleration sensor use CAN signals to pass on the required information to the electronic control unit for regulating the hydraulic pressure.
The ingenious ACTIVE CURVE SYSTEM uses its hydraulic system to pump oil from the oil container into the system. The pressure regulator integrated in the valve blocks of the front and rear axles and the directional valves set the desired pressure and turn the active stabilisers in the correct direction depending on the driving situation. The hydraulic rotary actuator integrated in the active stabilisers has six oil-filled chambers in its interior, and of these three are used to apply pressure for each driving direction, i.e. left and right-hand curves. In addition, the front valve block is responsible for distributing the oil flow between the two axles independent of load.
No stopping the GL off-road with new OFFROAD driving program
Every GL-model has an extensive standard off-road package for going on tours off the beaten track. In addition to its permanent four-wheel drive 4MATIC and electronic traction control 4ETS, this includes an off-road button which activates a special off-road driving program:
In addition, the START Assist and the HOLD function support the driver when starting off on a hill. The Downhill Speed Regulation (DSR) automatically keeps GL-Class vehicles at the speed set using the Tempomat lever.
Extended range of programs with ON&OFFROAD package
The ON&OFFROAD package for the new GL-Class with its six driving programs improves both vehicle dynamics and handling safety as it provides the best drive control available for very varying operating conditions both on and off-road. There is a perceptible improvement in comparison with the Offroad-Pro Technik package which has been on offer for the G-Class up to now. Up to now there was one top driving program for on-road driving and one for going cross-country. The new package has one automatic program, two special off-road programs and three road programs at its disposal. The specific driving programs for four-wheel drive provide the solution to the conflicting aims which have made life difficult up to now for the further development and research of the 4MATIC, the electronic traction system 4ETS as well as ESPÂ® and ASR. For instance: On off-road tracks it is important that the control systems regulate very gently because of the low friction values - but that makes it almost impossible to have a sporty tuning On the other side of the coin, a sporty basic tuning reduces the vehicle's performance off-road. In the past, engineers have always found very good compromises which functioned - and still continue to function - outstandingly in every situation. However, the new ON&OFFROAD package with its six specific driving programs allows both vehicle dynamics and handling safety to be optimised even more for every driving situation.
The programs are activated via a rotary switch on the central console. At the same time AIRMATIC, ADS, drivetrain and electric steering are adjusted to suit the specific requirements. The six driving programs are:
Despite the diversity, the driver is always in the position to make the right decision: It is easy to select the right program, the program selected is shown in the multifunction display in the instrument cluster as well as almost photo-realistically visualised on the COMAND screen. If the driver, for example, selects the program 'Winter', the display shows the Mercedes-Benz GL-Class in snow; the program 'Sport' shows a racing track with red-white kerbs, 'Offroad 1 and 2' show cross-country formations with different contours. The depiction shown is also interactive: the steering angle and spring travel correspond to the real values. In addition the display gives additional information about the steering, climbing and tilting angles, the AIRMATIC level, the pre-selected speed for driving downhill (Downhill Speed Regulation, DSR) and the selected drivetrain settings with reduction gear and lock.
Reduction gear, DSR or the AIRMATIC level control system can all be selected individually regardless of the drive program chosen. Just as with the basic settings for the ON&OFFROAD package, the driver cannot make a mistake here either. Settings which are not logical and which have a negative influence on the handling of the vehicle, its safety or traction, are excluded. If there is any doubt, the automatic mode is activated.
From the "hardware" point of view, the ON&OFFROAD package comprises a steel underrun protection for the engine, fibre-reinforced underfloor panelling, a two-stage power transmission with reduction gears, a longitudinal differential lock and extended AIRMATIC functions allowing a maximum ground clearance of 306 mm and fording depth of 600 mm.
A premium S-Class ride with higher vehicle dynamics both on and off-road
Research and development engineers in the Mercedes Technology Centre have perceptibly improved the quiet-running and low vibrations of the new GL-Class by working extensively on the details, thus setting a clear sign in the market segment for luxury SUVs. In this regard, the model lies on a par with luxury saloons like the S-Class. The improvements in detail:
Once upon a time: More comfort = more weight
A perceptible improvement in riding comfort with a simultaneous reduction in the weight of the vehicle by 90 kg has been achieved by using innovative approaches. In this way the new GL-Class and all current automotive developments at Mercedes-Benz have made their farewells to an old conflict of aims: Up to now, any increase in comfort has been at the expense of the vehicle's weight. The plastic engine support, the rigid cockpit cross beam made of high-strength magnesium alloy or the electric steering are among the outstanding examples of the "weight-optimised increase in comfort". The highly insulating front windscreen and the optional side windows using multilayer glass technology give much better sound insulation, but weigh less than conventional multilayer glass. The weight savings on the axles and alloy wheels are also extremely impressive. The weight per axle is reduced by 18 kg by using high-strength aluminium alloys. In this way the "unsprung mass" - a decisive parameter with respect to comfort - is reduced. The lower the weight of the wheels and axles, the less they are activated when driving over potholes or uneven surfaces. As a result, suspension and shock absorbers are not required to work as hard for a calming effect. So, to put it simply: A reduction in wheel suspension activation and the ensuing calming means a more comfortable ride.
While looking for other ways of increasing riding comfort, the engineers made a find in the GL roof. Up to now, the automatic tailgate was operated by a hydraulic drive situated at the rear in the upper frame of the roof. In the new model, the hydraulic system has been replaced by an electric spindle. This may save "only" two kg, but they have a significant effect on the handling as weight-saving measures on the roof of a vehicle way above the centre of gravity are much more effective than comparable weight reductions, for instance on the underbody.
Visibility and safety: The GL-Class - Complete awareness
Mercedes-Benz has based its development of active and passive safety for the GL-Class on the findings of the company's own accident research, which began more than 60 years ago and which to this day makes a significant contribution to the continued evolution of automobile safety. Besides this wealth of experience, the latest insights gained from detailed simulations and extensive testing are of course also incorporated in development and translated into concrete safety measures.
In conjunction with the assistance systems' "electronic crumple zones" and the intelligent bodywork design, the occupant protection systems provide the highest-possible degree of safety. An overview of the latest-generation restraint systems:
Passenger compartment encloses occupants like a protective cocoon
In a frontal crash, the front-end assembly can absorb impact energy and thus attenuate the peak loads on the occupants. The front-end structure essentially comprises two straight front longitudinal members, a second upper longitudinal-member plane and a subframe that supports the drive unit, connects the structure's two halves and deforms when subjected to high frontal impact loads. The lateral connections in the front-end activate the side opposite of the impact point in offset frontal impacts. The long front-end, short V-engines and the articulated shaft with its deformation element also contribute to the front-end assembly's deformation potential. In the event of major deformations, the wheels are supported against the strong bulkhead. The bulkhead itself is reinforced by an exterior cross member resting against the A-pillars above the pedal floor.
The passenger compartment's strength is tailored to the deformation resistance of the front-end assembly and envelops the occupants on all seven seats like a protective cocoon. The outstanding rigidity and strength result in part from the floor system with its separate transmission tunnel and longitudinal members integrated into the sidewall that, together with cross members set onto the floor, forms a stable supporting structure. The high-strength sidewall assembly comprises the body pillars, the lateral roof frame and the lateral longitudinal members. The sidewall assembly's outer shell is formed by the outer panelling. The inner shells are partially made up of several components with large-surface nodes between the pillars, roof frame and lateral longitudinal members.
The dual-shell A-pillar with its maximum-strength interior reinforcement is stabilised along the transverse line by the front roof frame and various cross members. The latter are located in the area beneath the windscreen, above the pedal floor and below the dashboard. An effective protection concept has also been implemented to account for rear impacts. Long deformation paths thanks to box-shaped rear longitudinal members, the location of the fuel tank ahead of the rear axle and of the filler neck above the rear axle provide a high energy absorption capacity in the event of rear-end collisions.
The Mercedes-Benz GL-Class also provides the greatest possible protection for more vulnerable traffic participants such as pedestrians and cyclists. Besides the yielding areas of the front-end, the folding exterior mirrors and the smooth contours, the risk of suffering injury from impact with the vehicle has been reduced through modifying the bonnet and increasing the distance to the components in the engine compartment. In addition, the active bonnet is a standard feature. It has the potential to reduce the severity of any injuries suffered by an impacting pedestrian or cyclist and further increases the deformation space. To optimise trigger criteria detection, acceleration sensors have been additionally integrated into the front bumper.
The GL-Class easily meets new crash requirements
In developing the GL-Class, the test specifications and criteria for accident testing applied in-house went far beyond those required by law. The GL was therefore perfectly able to fulfil even the most stringent requirements of the most important international test institutions:
Thanks to its comprehensive protection concept, the GL-Class has the potential to achieve excellent marks in all international crash ratings.
Assistance systems act as "electronic crumple zone"
Further optimisation of driving and condition safety in the new GL-Class is provided primarily by the numerous assistance systems' capacity to pre-empt accidents by acting as an "electronic crumple zone".
In addition to the driving dynamics control systems ESPÂ® and 4ETS, the Mercedes-Benz GL-Class comes as standard with the electronic brake control system ADAPTIVE BRAKE that improves traction, driving safety and operating comfort. The ADAPTIVE BRAKE electronic brake control system comprises the basic anti-lock braking (ABS) function and anti-slip regulation (ASR) as well as GMR active yaw control. ABS and ASR primarily monitor and affect longitudinal dynamics while GMR controls lateral driving dynamics. Where critical driving conditions are detected, and where physics will allow, selective wheel braking and engine torque adjustments are applied in order to maintain or recover traction and driving stability. In addition, ADAPTIVE BRAKE communicates with all other assistance systems and further comprises the following functions as standard:
With the GL-Class, COLLISION PREVENTION ASSIST premieres in the SUV segment. Also featured at no extra charge are the fatigue detection system ATTENTION ASSIST and a steering assistant. Optional systems such as the distance and cruise control system DISTRONIC PLUS, BAS PLUS Brake Assist or PRE-SAFEÂ® BRAKE featuring autonomous braking are also available to increase safety in the event of hazards not recognised by the driver. The available options also include Active Lane Keeping Assist, Active Blind Spot Assist and Speed Limit Assist.
Radar-assisted COLLISION PREVENTION ASSIST
Almost fifty percent of all rear-end collisions can be prevented, or their severity reduced, with the aid of radar-based safety systems such as collision warnings and adaptive brake assistants. This has been shown by the detailed analyses performed by Mercedes-Benz accident research. It is here that experience with the Mercedes-Benz innovations DISTRONIC PLUS and BAS PLUS pay off. With the GL-Class, an SUV will now feature such a system for the first time: COLLISION PREVENTION ASSIST. Unlike conventional systems, this new brake assistant is not merely a purely urban-driving system designed to minimise trifling damage. The innovative solution aims instead to provide protection against typical rear-end collisions in all traffic situations. The company expects the collision warning system to have a significant and positive effect on accident occurrence statistics. Test results underscore this assessment: in simulator tests with drivers, COLLISION PREVENTION ASSIST was shown to reduce the accident rate in three typical accident scenarios from forty-four to eleven percent.
COLLISION PREVENTION ASSIST issues visual and audible warnings when detecting obstacles to drivers who may be distracted and prepares the brake assistant to apply the brakes as precisely as possible. This brake application is then triggered as soon as the driver exerts pressure on the brake pedal. The system also meets the fundamental "Forward Collision Warning" requirements of the US National Highway Traffic Safety Administration (NHTSA) and is capable of:
In the extreme range of driving physics, drivers are also aided substantially by a number of systems, including the steering assistant which, for instance, helps the driver by applying steering torque to the steering wheel when the vehicle oversteers. An innovation and a highlight in the new GL is the standard Crosswind Assist, which uses targeted brake application to aid the driver when driving in high transverse wind force conditions, thus increasing the perception of safety and comfort.
Stability even in sudden crosswind gusts
The driving situation is well-known: when driving on high-quality country roads or dead straight stretches of motorway, the occupants suddenly perceive a forceful blow from the side, for instance when overtaking a truck, driving onto a bridge or at the end of lateral constructions such as noise abatement walls. The vehicle has been hit by a crosswind gust. Drivers of the new GL need not fear such gusts of crosswind as the driving dynamics control systems reliably compensate for these meteorological assaults and keep the vehicle firmly on course. Depending on the direction and intensity of the crosswind, the control systems apply corresponding brake pressure to the wheels and compensate, or at least substantially mitigate, the wind's effects on the vehicle. The intervention manoeuvre is handled by ADAPTIVE BRAKE. The required information is supplied by the sensors of the Electronic Stability Program ESPÂ®, the AIRMATIC ADS air suspension and the electromechanical steering.
If the system identifies a necessity to intervene, the driver is assisted through brake application on the front and rear wheel on the upwind side. This intervention results in a steering effect that reduces the impact of the crosswind. Crosswind Assist is active when driving straight ahead or through light bends at a speed of 80 km/h or more. The driver always remains in control: in the case of substantial and/or rapid steering corrections, Crosswind Assist is automatically suspended. The system filters minor crosswinds and only becomes active at a certain threshold. Continuous, constant crosswinds are also ignored. Research has shown that the latter driving situation affects comfort and perceived safety far less and is intuitively compensated for by drivers.
Back on track with the steering assistant
The standard steering assistant becomes active whenever the assistance systems identify unstable driving conditions that can be eliminated through simple steering actions. The system determines a steering torque corresponding to the driving condition and applies this torque through the electric power steering. When oversteering - the vehicle's rear creeping toward the outer edge of the corner - the steering assistant requests the driver to countersteer via the steering wheel until the vehicle has once again stabilised. The second primary feature is assistance when braking on a surface that displays different friction coefficients on the right and left of the vehicle, as is the case for example on partially iced-up carriageways in winter. The steering assistant notifies the driver of the direction in which the steering wheel should be turned in order to neutralise the yawing impulse. Even if the driver ignores the steering assistant's recommendations, ample reserves remain to stabilise the vehicle in the form of the driving dynamics systems such as ADAPTIVE BRAKE, ESPÂ® or 4ETS. The steering assistant is always available to provide the driver with recommendations, but never takes over.
Even after a crash: occupant protection
After a more substantial crash, the hazard warning lights are switched on automatically in order to warn the surrounding traffic. At the same time, the door locks are automatically disengaged in order to facilitate the best-possible access to the vehicle occupants for emergency services. Thanks to the partial opening of the side windows, the interior is more efficiently ventilated after restraint systems have triggered.
Where a collision is detected, the central control unit shuts off the fuel system. After determining the cylinders' positions, the engine management opens the injectors on cylinders not in compression stroke and relieves the fuel high-pressure area by releasing the remaining fuel directly into the combustion chambers. This reduces the risk of fuel escaping. As a further measure to prevent fuel from escaping, the relevant points feature cut-proof fuel lines and this also increases safety in the event of a collision.
If COMAND Online is chosen for the new GL-Class, the automatic Mercedes-Benz emergency call is included as standard. In the event of a serious accident, emergency services are notified automatically and within minutes are furnished with extensive information on the precise accident location or the respective vehicle model. The operating principle: if airbags or belt tensioners are triggered in a crash and COMAND Online is connected to a mobile phone, the system transmits the vehicle's precise GPS location and its chassis number (VIN) to both the emergency services and the Bosch Communication Center's service control room by text message. The location data is also transmitted by DTMF (dual-tone multi-frequency). Even if the occupants are unconscious or do not know their precise location, for example when on holiday, the emergency services called by the Communication Center can be informed precisely and rapidly.
The vehicle also quickly establishes a voice connection to the Bosch Communication Center. The language used does not correspond to the respective country's language but to the language set in COMAND Online by the driver. Emergency calls can also be placed manually as the "Mercedes-Benz emergency call" entry is always located at the very top of the phone book list. With the launch of the GL-Class, the emergency call will be able to access the phone network in nine European countries: Germany, France, Italy, Spain, the United Kingdom, Austria, Belgium, the Netherlands and Switzerland. By late 2012, nineteen further countries will be added. Apart from any possibly applicable mobile phone rates, a Mercedes-Benz customer will incur no costs for using the Mercedes-Benz emergency call service.
The GL sees all: 360Â° camera, NightView Assist PLUS and off-road lights
Together with the compact character GLK, the GL-Class will be available for the first time with the 360Â° camera. The 360Â° camera is always combined with PARKTRONIC and is supplied with imaging information by a total of four cameras located respectively in the radiator frame, in the tailgate above the number plate and in the two exterior mirrors. The system uses the imaging information to compile various views, among them a depiction of the vehicle and its surroundings from a bird's-eye perspective. Occupants view the picture in real time in the central COMAND display. This allows the areas behind, in front and to the side of the vehicle to be observed and can thus prevent collisions in a multitude of different manoeuvres both on- and off-road. Supplemented dynamic guiding lines assist orientation. For example, the 360Â° camera indicates the vehicle's turning area in accordance with the steering-wheel angle.
The 360Â° camera is automatically activated when reverse gear is engaged or when selected directly in COMAND. The camera images in the display switch depending on the transmission position selected: when reverse is engaged, the display automatically shows the image relayed by the rear camera. Bird's-eye view or the individual images can be selected by the driver by means of the COMAND controller at any time. Specifically, the 360Â° camera can provide assistance to the driver through the following functions:
For the first time, the cameras in the GL now feature high-performance digital CMOS image sensors (Complementary Metal Oxide Semiconductor). Each camera processes images at a resolution of one megapixel and covers a 180-degree field of vision. The views compiled from the four individual images by the system and shown in the COMAND display are of impressively high quality. The virtual bird's-eye view is almost entirely distortion-free. Unlike the familiar systems, which utilise black bars to separate the individual images, the 360Â° camera displays the total image homogeneously without transitory elements. In addition, the 360Â° camera adapts to the various vehicle heights, for example if the maximum-possible ground clearance of 600 millimetres that comes with the ON&OFFROAD package has been chosen. The driver is also kept aware of the surroundings when manoeuvring at night. At speeds of up to 10 km/h with the headlamps switched on, activating the 360Â° camera also activates the surround lighting. The 360Â° camera also offers another special feature that prevents occlusion of the rear camera through soiling, for example during long journeys through muddy terrain or when driving on wet, salt-strewn motorways in winter. A flap covers the camera and provides reliable protection from soiling. The flap opens automatically when the 360Â° camera is activated.
NightView Assist PLUS turns night into day. The optionally available assistance system utilises two infrared headlamps. The emitted long-wave light is invisible to the human eye and covers the carriageway ahead of the Mercedes-Benz GL-Class at a range corresponding to main beam. The camera located in the windscreen in the area of the rear-view mirror records the infrared image and, after processing by the control unit, relays it to the COMAND display. Here, the scene is depicted in high-definition grey-scales. Detected pedestrians are additionally highlighted by "photo corners" to make them even more easily visible. The system is available at full performance as of a speed of 10 km/h.
When driving in difficult terrain at low speeds, it is useful to illuminate the area ahead of the vehicle as brightly and as widely as possible. The new GL, if equipped with the ON&OFFROAD package in conjunction with the Intelligent Light System, will feature special off-road lights that provide precisely such illumination. If the driver activates either the OFFROAD 1 or the OFFROAD 2 driving program while the headlamps are switched on, the off-road lights are automatically activated as well. The bi-xenon headlamp modules are swivelled outward through six degrees, the xenon burners output is increased by 3 watts and the light cone is set to symmetrical. In addition, the LED cornering lights on both sides are switched on permanently, while both the dynamic cornering light function and the headlamp beam adjustment are deactivated. These settings combine to give a wider and brighter illumination of the area ahead of the vehicle than is provided by the Intelligent Light System, configured for optimal illumination when driving on roads. Orientation during off-road driving is substantially improved and any obstacles can be seen earlier. The off-road lights are active at speeds up to 50 km/h. When the driver exceeds this threshold, the Intelligent Light System automatically resets the lighting functions to optimum road operation.
As 40% of all serious accidents occur at night, the temperature of the xenon burners used by the Intelligent Light System has been raised to 5,000 Kelvin to further increase safety. This results in an illumination very similar to daylight, which improves comfort and relieves the strain on the driver.
Braving the gap: Active Parking Assist
The new-generation Active Parking Assist utilises ultrasonic sensors at a speed of up to 35 km/h to identify potential parking spaces along the road on the side the vehicle is travelling on, or on both sides in one-way streets. Suitable parking spaces are indicated in the central display. The driver can then start Active Parking Assist by pressing a button on the multifunction steering wheel. The system calculates a suitable trajectory from the vehicle's current position. The driver then only needs to accelerate or brake - the required steering motions are completed fully automatically by the system. Departing from parking spaces works the same way.
Active Parking Assist comprises six ultrasonic sensors in the front bumper and four in the rear bumper. The ultrasonic sensors on the corners of the front bumper have a greater range than the other sensors in order to facilitate reliable detection of parking spaces when driving past them.
Get your bearings: parking and manoeuvring aids through the years
In the early days of the automobile at the beginning of the last century, car manufacturers were already thinking about ways to aid drivers in keeping an overview when manoeuvring their vehicles. First efforts using a variety of marker rods on the outer ends of the bumpers only caught on with commercial vehicles. In 1959, with the Mercedes-Benz passenger car models referred to as "tailfins", the first real attempt was made to integrate orientation aids into the general design concept of a car. The tailfins on Mercedes-Benz medium-sized and premium-class saloons, officially termed marker bars, facilitated excellent estimation of the body's position, in particular when glancing obliquely over one's shoulder such as one might do when parking. For a long time, the more or less substantial bulges on the rear wings remained the tool of choice.
This did not change until the early 1990s and the new model series 140 S-Class. At up to 5.20 metres in length, the premium-class car offered its occupants superior space in the interior but also required aids to make the rear end of the body visible when manoeuvring. The solution: extendable, chrome-plated marker bars on the rear wings that were pneumatically lifted when reverse gear was engaged, thus providing a visualisation of the S-Class's rear end. Though effective, the mini-aerial solution did not correspond to the technology levels associated with Mercedes-Benz's top-range model over the long term.
Consequently, the developers went to work and, in 1995, presented the revolutionary PARKTRONIC system. The new system adopted a natural model by adapting the ultrasound orientation system familiar from bats and combining it with highly sophisticated electronics. The distance to obstacles was indicated by coloured LCD displays in the dashboard. If the driver ignored the displays, closer approaches were accompanied first by a clearly audible intermittent tone and then by a continuous tone warning of imminent collision.
Parking Assist, available for the S-Class as of 2005, provided even greater precision by relying not on ultrasound like PARKTRONIC but on the radar sensors of the DISTRONIC and Brake Assist PLUS systems. The advantage compared to the bat principle: the territory monitored around the vehicle was significantly larger. Here too, the driver was notified of his territorial behaviour by way of the typical beeping. Visually, however, a colour display in the instrument cluster now provided substantially greater details on the manoeuvring course. In addition, engaging reverse gear also automatically activated an additional display in the rear roof lining.
In the same year, the first reversing camera premiered in the S-Class, available then in conjunction with PARKTRONIC which was still on offer. The camera eyed the surroundings from the boot lid above the number plate, relaying its image to the COMAND display once reverse gear was engaged. The system's electronic director also calculated the optimum path into the targeted parking space and supplemented the camera's image with corresponding guiding lines.
In 2008, searching for a parking space and parking "manually" became a thing of the past. The then latest generation of the A- and the B-Class were offered to Mercedes-Benz customers for the first time with the option of Active Parking Assist. The electronic passenger kept an eye open for parking spaces on both sides of the vehicle up to a speed of 35 kilometres an hour. Once it found a parking space, the driver was not only happy but also relieved that the following manoeuvring was taken off his hands. An arrow in the instrument cluster indicated the side on which the parking space was located. The driver then needed to engage reverse gear and give the go-ahead by pressing a button on the multifunction steering wheel. The assistant then took over steering while the driver needed only accelerate and brake.
A further step followed only a year later. Parallel to Active Parking Assist, the E-Class was offered with the classic PARKTRONIC including the new parking guidance. This version also looked for parking spaces as described above. However, the driver here needed to handle the steering himself, albeit with the aid of indicators in the instrument cluster display describing the necessary steering manoeuvres. The climax in development of parking and manoeuvring assistants, at least for the present, are the GL-Class's Active Parking Assist with automatic parking and departing function as well as the 360Â° camera that displays the surroundings to the driver from a variety of perspectives: from the complete panorama of bird's-eye view to the various detailed views that facilitate down-to-the-centimetre precision manoeuvring even in difficult terrain.
Drive and efficiency: More driving pleasure - lower consumption
Both the GL 350 BlueTEC 4MATIC's BlueTEC diesel engine as well as the GL 500 4MATIC BlueEFFICIENCY's turbocharged BlueDIRECT V8 petrol engine offer exhilarating performance combine with high efficiency. On average, the new range's models consume 18 or, respectively, 20 percent less than their predecessors - while output has been substantially increased.
The GL 350 BlueTEC 4MATIC with SCR technology and AdBlueÂ® injection today already meets the requirements of the emissions standard EU 6 planned for 2014. At a consumption of 7.4 - 8.0 l/100 km (NEDC combined), the diesel model consumes 20 percent less than its predecessor. CO2 emissions of 192 grammes per kilometre are the best value in this output segment. Despite the significantly reduced energy requirements, performance has been substantially increased. While the first-generation GL 350 BlueTEC's output was 155 kW (211 hp) and its maximum torque was 540 Newton metres, the new model now achieves 190 kW (258 hp) and 620 Newton metres. Together with the output, the capacity for acceleration and the top speed have of course also increased.
The GL 350 BlueTEC 4MATIC is among the cleanest diesel-powered SUVs in the world: BlueTEC is a technology developed by Mercedes-Benz that reduces diesel-vehicle emissions, particularly nitrogen oxides. The system injects AdBlueÂ®, an aqueous urea solution, into the exhaust flow. This releases ammonia which then reduces up to eighty percent of the nitrogen oxides to harmless nitrogen and water in the downstream SCR catalytic converter (Selective Catalytic Reduction). The result: the model today already meets the emission values required by the EU 6 standard planned for 2014. The AdBlueÂ® tank is located under the luggage-compartment floor to protect it in the event of a crash, has a capacity of 31.2 litres and is refilled at the regular 25,000-kilometre maintenance intervals. The filler aperture is located behind the fuel filler flap on the side of the vehicle, behind the fuel filler neck, and is easily recognisable by the bright blue cap. GL drivers can thus easily refill the tank themselves if they make intensive use of the GL's off-road capabilities and happen to find themselves beyond the frontiers of civilisation without access to a service station. AdBlueÂ® is available in refill containers at every Mercedes-Benz dealership. The need for a refill is indicated in good time in the instrument cluster.
Superior thrust - the GL 500 4MATIC BlueEFFICIENCY
With NEDC consumption figures of 11.3 - 11.5 l/100 km, the GL 500 4MATIC BlueEFFICIENCY features the most economic V8 petrol engine in its class. The engine is a turbocharged 4.6-litre BlueDIRECT power unit with 320 kW (435 hp). The latest generation consumes an average eighteen percent less fuel and, thanks to EU 5-compliance, offers the best classification presently available.
The new V8 engine produces 320 kW (435 hp) from 15 percent less cubic capacity (4663 compared to 5461 cc), roughly 12 percent more power than its predecessor's 285 kW (388 hp). At the same time, torque has been increased from 530 to 700 newton metres - a 32-percent increase. As the high maximum torque is already available at only 1,800 revs, the new V8 produces superior power even at low engine speeds and provides a smoothness of performance that is exemplary even for an eight-cylinder engine. Mercedes-Benz's engineers achieved the higher output from the lower cubic capacity primarily by means of two exhaust-gas turbochargers - one each per cylinder bank.
The turbochargers are designed to provide high torque even at low engine speeds - compared to the predecessor's engine, they produce above 40 percent more at 2,000 rpm. Outstanding 700 newton metres are available in the range from 1,800 to 3,500 revs. The driver will thus notice no turbo lag, instead perceiving the new V8 as pleasant and powerful. The latest generation of engines also incorporates such innovations as the third-generation direct injection featuring guided-spray combustion and piezo-injectors as well as multi-spark ignition.
GL63 AMG: efficiency and driving dynamics of the highest degree
With the shift to the new model range, the GL is for the first time available as an AMG variant. The high-performance SUV GL63 AMG features an AMG 5.5-litre V8 Biturbo engine with 410 kW (557 hp) and a maximum torque of 760 newton metres, resulting in superior driving performance: the GL63 AMG accelerates from zero to 100 km/h in 4.9 seconds; top speed is 250 km/h (electronically governed). NEDC consumption is 12.3 litres per 100 kilometres (288 g of CO2/km).
The AMG eight-cylinder designated M157 features an innovative high-tech package comprising guided-spray petrol direct injection, piezo injectors, biturbo charging, air/water charge air cooling, fully aluminium crankcase, four-valve technology with camshaft adjustment, generator management and ECO start/stop.
Power is transmitted to the four permanently driven wheels by the AMG SPEEDSHIFT PLUS 7G-TRONIC. The seven-speed gearbox impresses with its high variability gained through the three driving programs and the automatic double-clutching function for downshifts. In "Controlled Efficiency" (C) mode, ECO start/stop is active and switches off the eight-cylinder engine whenever the vehicle comes to a standstill. "C" also incorporates a soft accelerator-pedal and gearbox characteristic with early shift points; in this mode, the vehicle generally pulls away in second gear. An "ECO" icon in the AMG instrument cluster tells the driver that ECO start/stop is active.
A further increase in efficiency is provided by the AMG SPEEDSHIFT PLUS 7G-TRONIC automatic gearbox featuring a fuel-economy torque converter with mass-damper pendulum, low-friction bearings and thermal management for the transmission fluid. Additional fuel-consumption reductions are achieved by low-friction axle drives, the electromechanical AMG speed-sensitive sports steering, the optimised belt drive and the adaptive management of all auxiliary units and pumps.
For the 4MATIC permanent four-wheel drive, Mercedes-AMG employs an autonomous transfer case: it distributes drive power between the front and rear axle at a ratio of 40:60 to achieve a high degree of driving dynamics. And there's more: the AMG RIDE CONTROL sports suspension with AIRMATIC package, comprising air suspension, special spring struts, automatic ride height adjustment and the Adaptive Damper System (ADS), is combined with ACTIVE CURVE SYSTEM anti-roll stabilisation.
Reduced energy requirements thanks to BlueEFFICIENCY
Besides the state-of-the-art engine technology, fuel economy is further aided by a comprehensive package of BlueEFFICIENCY measures. These include, in addition to the standard ECO start/stop, the new 7Gâ€‘TRONIC PLUS seven-speed automatic gearbox. Further fuel-consumption reductions are achieved by the low-friction axle drives, electric steering and low-rolling resistance tyres.
The redesigned 7G-TRONIC PLUS comes as standard for the models GL 350 BlueTEC 4MATIC and GL 500 4MATIC BlueEFFICIENCY and is characterised by integrating ECO start/stop, by its reduced torque converter clutch slip and its optimised efficiency. The most important details include the new torsion damper that now attenuates rotational imbalances and vibration in the gearbox even more effectively. Such vibration becomes potentially greater the lower the engine speed and the lower the number of cylinders. This results in a conflict of interests between comfort and economic operation. The conflict is resolved by employing a so-called twin-turbine damper which, in the diesel models, additionally features a mass-damper pendulum. The damper shifts the centre of gravity in accordance with the engine speed and facilitates comfortable vehicle operation even in the economic operating range. Additionally, the optimised damping also allows for a substantial reduction in torque converter clutch slip even at low loads, again contributing to better fuel economy. The optimised attenuation of imbalances and vibration in the gearbox also ensures a faster response to accelerator pedal actuation. Low-friction bearings and a new thermal management for the transmission fluid further reduce fuel consumption.
The energy requirements of the new GL-Class are reduced even more by an optimised belt drive with decoupler and the intelligent, adaptively controlled activation of all auxiliary units and pumps. In the same way as the fuel pump in the vehicle's rear, the engine's oil and water pump are activated only as far as required by the actual loads. The same control logic is also utilised in the standard THERMATIC (GL 350 BlueTEC 4MATIC) and THERMOTRONIC (GL 500 4MATIC BlueEFFICIENCY) climate control systems, which activate the refrigerant compressor only when necessary. In addition, an internal heat exchanger and the sophisticated sensor system including a misting sensor on the windscreen ensure the highest-possible efficiency for passenger-compartment climate control. Also significant in the case of the diesel model is the flow and counter pressure-optimised BlueTEC exhaust system with AdBlueÂ® injection.
Less drag through sophisticated aerodynamics
With a drag coefficient of cd = 0.35 (GL 350 BlueTEC), the new GL-Class improves upon its predecessor and takes a peak position in its market segment (overall drag cd x A = 1.05, predecessor 1.07). Intense simulations as part of the digital prototyping process as well as fine-tuning in the wind tunnel have provided for perfect airflow around the vehicle. An overview of the most important aerodynamic improvements:
Findings from the "energy-transparent vehicle" put to good use
The Mercedes-Benz GL-Class's energy efficiency has also been improved by applying experiences gained from the energy-transparent vehicle (ETV), a process first employed during the development of the M-Class. Through high-precision, in-depth examination of the energy flows within the entire vehicle (tank-to-wheel), engineers are capable of optimising all consumption-related assemblies - right down to individual components such as the wheel bearings. The notion of the ETV arose from the fact that, in the past, many consumption effects and correlations between economy measures could not be conclusively verified or validated. Thanks to the ETV, developers can now identify in detail the optimisation potential by breaking down the energy-related causal loops and by analysing the correlations within the overall vehicle.
The process utilises extremely complex high-precision measurement technology capable of recording up to 1,000 measurement values per second at around 300 energy-related measurement points. Thus, approximately 2.4 million values are obtained per minute. Their analysis provides reliable indication of optimisation potential. The process is supplemented by energy simulation models that are validated by means of measurement values. In combination, these procedures facilitate analysis and quantification of the energy efficiency of individual units and components as well as of the entire vehicle.
Where the specialists identify a vehicle component with dissatisfactory energy efficiency, solutions are developed in collaboration with the technical departments. These solutions can focus, on the one hand, on design or material properties of individual vehicle components such as wheel or axle bearings but may also be achieved by modifying control strategies.
Dietary measures for improved agility and efficiency
Thanks to extensive lightweight design measures, a reduction of the new GL's weight by 90 kilogrammes compared to the predecessor model (GL 350 BlueTEC 4MATIC) has been achieved - in spite of additional equipment such as the standard sliding sunroof, the significantly improved second row of seats with easy-entry on both sides of the vehicle, the optimised crash characteristics and the noise-reduction measures. The front and rear-axle links as well as the bonnet and the wings, for instance, are made of light but strong aluminium alloys. The further weight reduction was achieved through the new high-insulation windscreen, the dashboard's magnesium cross beam, the BlueTEC system with SCR technology or components such as the new electromechanical steering, the electric parking brake, the plastic engine bracket or the new aluminium brake booster.
Long-distance travel with less refuelling stops
Particularly impressive is the range of the new GL-Class on just a single tank. This parameter is especially important in a terrain-going vehicle that is able to get almost anywhere. At an NEDC consumption of 7.4 l/100 km, the particularly economic compression-ignition engine of the GL 350 BlueTEC 4MATIC with the standard 100-litre fuel tank can cover around 1,350 kilometres without a refill. The GL 500 4MATIC BlueEFFICIENCY's V8 petrol engine achieves a range of up to 890 kilometres before requiring refuelling.
Development and Production: Digital worlds in real vehicles
With the new Mixed Reality development tool, which Mercedes-Benz fully implemented for the first time during the development of the new GL-Class vehicle, it was possible to link data from the "Digital Prototype" development program to real experimental vehicles directly for the first time. The advantage of this new method - also known by the generic term Augmented Reality - lies in the ability to speed up the entire development process significantly. However, Mercedes-Benz does not just use this accelerated process to shorten development times. The Mixed Reality engineers use it to conduct far more trials within the same time span, which significantly improves the quality of the overall development process.
Previously, digital and real processes ran consecutively: early studies were conducted during the initial development phase in the virtual environment. To ensure that these solutions could be put to the test in real-life situations, mock-ups and part builds, such as seating configurations for ergonomic studies or complete vehicle prototypes, were then produced. Engineers then made decisions either using computers in the virtual world or directly affecting the real builds. Mixed Reality linked these two worlds, the digital and the real, thus introducing completely new development perspectives. Modifications and new concepts from the virtual world can now be visualised, checked and assessed directly in the real-life environment.
Combining a virtual engine with a real vehicle
Mixed Reality first uses a camera to capture photos of a particular area of the prototype, such as the engine compartment. The precise spatial relationship between the real-life and digital world is established using tracking systems, which precisely determine the current position of the video camera in relation to the overall vehicle. These video images are then displayed on a monitor and a variety of different components are "installed" virtually. Typical examples of application include positioning new electrical components such as wiring harnesses or control units, optimised heat shields or hydraulic functional units such as the brake force booster with corresponding lines. However, it is also possible to conduct installation tests with new engine configurations. In this case, the engineers assess whether a modified engine will fit in the existing installation space or if it can be easily mounted during the production process. Special spatial analyses are used by developers to assess the accessibility of individual components within the engine compartment to ensure that installation and maintenance work can be easily carried out on the vehicle at a future date. The first validation of virtual models is taking place in the real world with the use of Mixed Reality. This process has meanwhile been firmly integrated into the Mercedes-Benz development program.
15 years of production in Tuscaloosa
With the start of production of the new GL-Class in the US automotive plant in Tuscaloosa, Alabama, an inspiring success story that began 15 years ago is being updated. Production in the plant started in 1997 following the ground-breaking ceremony in 1995. The site manufactured the Mercedes-Benz M-Class and later added the GL-Class and R-Class SUVs. In 2009 the plant employees had the opportunity to celebrate a very special anniversary: the one-millionth SUV, an ML 350 BlueTEC, left the production plant. In 2011 the plant produced more than 148,000 vehicles and employed approximately 2,800 people by year's end.
Starting in 2014, the next generation of the current C-Class for the North American market will also be produced at the Mercedes-Benz plant in Tuscaloosa, and in 2015 a fifth Mercedes-Benz model series will be added to the production portfolio.