Outrageous proportions: a long bonnet, narrow-look windows with frameless side windows, dynamic roof sweeping back at an angle towards the rear. In 2003 the four-door Coupé was born: and the Mercedes-Benz CLS-Class immediately established itself as a new style icon. The proportions have stayed the same – and yet everything is different: the second generation of this design trendsetter has adopted a completely new look.
What immediately strikes the eye is the innovative front design, which is reminiscent of the Mercedes-Benz SLS AMG. Visually, the radiator grille is not integrated into the bonnet but is formed separately. This highlights the long, sporty bonnet even further. The grille is dominated by the large central star, which underlines the car’s relationship to the other coupés of the brand and strengthens the brand identity. The large, elongated dark air inlets with black grilles also add to the vehicle’s athletic appearance.
Another distinguishing feature comes in the form of the LED High Performance headlamps, which are the world’s first to offer all of the regular dynamic light functions using LED technology. This innovation boasts an impressive design – inside it is divided into three arrow-shaped layers from top to bottom: the upper layer contains an LED indicator, beneath which is a striking LED side light offering LED low beam functions. The side light can also be seen when the dipped beam function is switched on, thereby creating a novel and separate night-time design as a distinctive look. The lowest level of the headlamp houses the main beam and nightview functions. A total of 71 LEDs not only provide an unmistakable appearance, but also offer a significantly enhanced view of the road compared with previous systems.
The typical Mercedes-Benz CLS-Class outline, with its elegantly long proportions, is the dominating attribute of the new model. The effect of the dynamic, athletic form has been enhanced with a new interplay of lines and areas. The front edge of the structure above the wings slopes off towards the rear. This novel design feature, called the dropping line by designers, represents a new interpretation of a formal design element harking back to the uniquely rich wealth of forms present in historic Mercedes sports cars.
A distinctive and muscular sports car-like shoulder line above the rear axle highlights the athletic character of the new CLS. The flared wheel arches resemble the powerful thighs of a feline predator waiting to pounce.
The side view is rounded off with wide wrap-around tail lights featuring LED technology which are arranged in the form of a linking element to the rear of the vehicle. The shape is emphasized by the broad shoulder line, which is clearly visible from behind and supports the flat hardtop. A wide metal insert adds a further visual highlight at the rear.
Quite apart from its breathtaking design, the vehicle body of the new Mercedes CLS spoils all occupants with its generous interior measurements: in particular, the four-door coupé offers more elbow room (8/21 millimetres at the front/back) and more shoulder room (21/13 millimetres) than its predecessor. The starting point for this extra space was the vehicle body, which is 29 millimetres longer, 13 millimetres higher and 8 millimetres wider than its predecessor. The wheelbase has increased too, by 20 millimetres to 2874 millimetres.
The boot has a capacity of 520 litres and, for the first time in the Mercedes-Benz CLS-Class, comes with EASY-PACK quickfold as an optional extra for the rear seat backrest which folds down in a 1/3:2/3 proportion. Up to 19 different places to store and secure objects throughout the car make it quick and easy to accommodate smaller objects. The EASY-PACK comfort box for the boot, which is an optional extra, provides even more stowage space. It is normally folded flat and stored under the parcel shelf. If the EASY-PACK comfort box is needed, it can be pulled out and folded down. Thanks to its flexible base, its volume can be varied from 7 to 55 litres. Its can bear a maximum of ten kilograms in weight. The box, which is some 530 millimetres wide, can be removed from the boot without the need for tools if its full capacity is required.
Stylish cockpit with three round dials and two colour displays
In addition to the “wrap-around effect” of the instrument panel support, the newly-designed multifunction steering wheel in the 3-spoke design in Nappa leather is particularly eye-catching. The steering wheel is available in black or almond beige; a wood-and-leather finish is also available as an optional extra. In the optional AMG Sports package there is a particularly sporty steering wheel which has a flattened wreath in the lower half. Both steering wheel options have 12 multifunction keys to control the infotainment functions.
The highlight of the exclusive CLS instrumentation is the all-colour, three-dimensional TFT display in the middle of the speedometer, measuring 109 millimetres in diameter. The mileage and trip odometer appear in the lower area of the display, the top displays – amongst other things – information from the driver assistance systems. A three-dimensional image of the vehicle appears when getting into or out of the Mercedes-Benz CLS-Class.
Three tube-shaped round dials in the cockpit inform the driver of the coolant temperature and fuel tank level (on the left), speed (in the middle) and engine rpm (on the right). A large colour display in 16:9 format, elegantly integrated into the upper part of the instrument panel support, gives information on all the infotainment functions. The TFT display (Active Matrix Thin Film Transistor), which is backlit with LED lights, uses so-called IPS technology. IPS stands for “in-plane switching”, which describes the shift direction of the liquid crystal. The benefit of this technology is that it displays high-contrast images which stay sharp outside the direct line of vision. Depending on the specification, two versions of this cutting-edge display are available: a 14.7 cm version for the Audio 20 and Audio 50 APS systems; and a high-resolution 17.7 cm variant for COMAND APS.
The centre console fits harmoniously with the shape and colour of the instrument panel. The control unit for the infotainment system and the optional car telephone can be found underneath the analogue clock and air vents. The push-button switches for seat heating, seat ventilation, the hazard warning lamps, rear window blind and other items of equipment ordered as options are arranged below this; they have been galvanised and are backlit. The large round control knobs for the automatic climate control, which is supplied as standard, are located in the lower part of the centre console. The controller in the tunnel trim serves as the central control element for the infotainment systems and provides a quick and easy starting point for navigating the well-organised menus controlling the systems.
THERMOTRONIC climate control with three individual climate modes
The second-generation Mercedes CLS can be optionally fitted with an automatic climate control system which not only allows individual temperatures to be set for three zones – for the driver, the front passenger and the rear passengers – but additionally offers special climate modes. This means that, if the optionally available THERMOTRONIC system is fitted, the car occupants can select “Diffuse”, “Medium” or “Focus” settings on the THERMOTRONIC at the push of a button and thus adjust the air quantity and air distribution to their liking without having to leave the convenient automatic mode.
In “Diffuse” mode, for example, the THERMOTRONIC system operates with a lower air speed and distributes the air over a wide area so that there are fewer draughts. This is the purpose of the automatically controlled, upwards inclined diffuse nozzle in the centre of the dashboard. In “Focus” mode, meanwhile, the air outlets in the centre area of the dashboard are used for the most part, meeting the need for a direct flow of a larger quantity of air. The standard system fitted in the CLS is the two-zone THERMATIC automatic climate control.
The ultimate in seating comfort allowing adjustments to suit individual ergonomic needs
Refined sportiness – this philosophy applies also to the seats, as they combine the ultimate in seating comfort with sporty lateral support. Four different front seat types are available to choose from:
- The standard seat itself meets the highest ergonomic standards. Thanks to the filled seat piping, the feeling of comfort simply when getting into the vehicle is unique. A special upholstery technology is deployed here, which inserts additional foam filling immediately beneath the cloth or leather upholstery. The front seats can be adjusted electrically as standard. The Memory package, which enables three individual settings to be saved, is available as an optional extra.
- The shape of the optional multicontour seat can be individually adjusted by and for the driver and passenger to fit their anatomy or to suit their personal wishes with regard to comfort. Thanks to an innovative technology for adjusting the seat side bolsters, for example, the width of the backrest can be adjusted on both sides in a stepless operation by up to 45 millimetres, i.e. by up to 90 millimetres in total. Other bonuses of the new multicontour seat include the pneumatic height adjustment facility for the seat cushion and the high-comfort head restraints.
- The active multicontour seat offers the same comfort functions and additionally has high-speed piezo valves in the air chambers which adjust the charging pressure and volume of the air chambers in the side bolsters of the seat backs, depending on the steering angle, lateral acceleration and vehicle speed, to provide both the driver and front seat passenger with even greater support. It also has the high-comfort head restraint and, additionally, a massage function.
- Climate comfort is further enhanced by the optionally available active climatised front seats, which are available as an optional extra. Four ventilators in the seat cushion and in the backrest extract cool air from the floor area of the interior and distribute it evenly through a ventilation tissue beneath the seat surface. The mild airflow can prevent the car’s occupants from sweating, even when it is extremely hot outside. Seat heating can also be selected for all four seats as an optional extra.
Individual seats for the passengers in the rear, for the first time fitted with ISOFIX child seat attachments
Two individual seats in the rear provide a particularly comfortable experience in the second row. These seats are well-liked for their extensive lateral support which comes from the contouring. There is a roomy stowage compartment in the centre armrest between the two seats, which if desired can also contain a cup holder for a bottle. An electrically-operated rear-window blind for the rear passengers is also available as an option, which can palpably and measurably reduce sunlight streaming in at the touch of a button. It is fixed to the C-pillars, as it is in the S-Class.
For the first time Mercedes-Benz is offering the Mercedes-Benz CLS-Class with ISOFIX, the international standard securing system for child seats. The mechanism is fitted as standard and comprises two retaining brackets in each rear seat position, in the gap between the back rest and seat cushion, as well as an additional third anchor point above the backrest, the so-called top tether.
Car radio, CD player and Bluetooth interface as standard
Nowadays, nobody wants to miss out on the news, the telephone, route guidance or music listening pleasure when in the car. For this reason Mercedes-Benz has equipped the new CLS with state-of-the-art infotainment facilities, which stand out for their high performance capability, but above all for their ease of use. They are called the Audio 20 CD (supplied as standard), Audio 50 APS and COMAND APS (supplied as optional extras).
All of the devices include speed-sensitive volume control, a keypad for entering telephone numbers and radio frequencies, a colour display in the centre of the dashboard, and a Bluetooth interface to connect a mobile phone to the hands-free system wirelessly. Eight loudspeakers supplied as standard and located in the doors ensure excellent sound quality.
Features of the Audio 20 CD system, fitted as standard, include a CD player (with MP3 capability), a dual tuner for FM/MW/LW/SW, automatic station search, RDS function (FM reception) and a 4 x 20-watt amplifier.
The AUDIO 50 APS infotainment system is an all-in-one device featuring a combination of car radio, DVD player and Europe-wide navigation system with two-dimensional map display. The radio functions and the options for linking with other systems are the same as for the Audio 20 system. Mercedes customers who opt for the version with integral six-disc DVD changer also receive the LINGUATRONIC voice-operated control system.
The COMAND APS multimedia system developed by Mercedes-Benz includes a DVD player for audio and video as well as a Europe-wide navigation system whose data are stored on a 40-gigabyte hard drive, allowing extremely fast access to the navigation data and, compared to DVD-based navigation, even faster route calculations. The high-resolution map appears on the 17.7 cm colour display in the centre of the instrument panel and excels in providing useful additional information. By way of example, the map shows the outlines of prominent buildings along the route to aid orientation.
Mercedes-Benz combines COMAND APS with the voice-operated control system LINGUATRONIC and a so-called text-to-speech function as standard. This makes it possible for route-related traffic reports, SMS messages, address book entries or radio station names to be read out to the driver. The system automatically reads out new traffic reports that are relevant to the current route.
Additional systems for the ultimate in listening pleasure and entertainment
Mercedes customers can, if desired, combine the infotainment facilities for the CLS with other systems:
- The Logic7 surround sound system developed by Mercedes-Benz together with the audio specialists harman/kardon® delivers an outstanding performance with three-dimensional sound as a natural 360-degree musical experience for all passengers.
- iPods, USB sticks or other external audio devices can link to the infotainment system of the new Mercedes CLS through a media interface in the stowage compartment in the centre console.
- A separate DAB tuner (DAB = Digital Audio Broadcasting) and additional aerials (optional) allow passengers on board the new CLS to receive digital radio stations in CD quality. The system switches to analogue reception automatically when the DAB signal is too weak.
The model range: Every CLS is a one-off
Individuality is written large in the new Mercedes CLS. The model range for the four-door Coupé is correspondingly extensive – it will be at first be available with rear-wheel drive and then, from September 2011 onwards, for the first time as a 4MATIC with all-wheel drive. As regards the drive system, customers will at first have a choice between four petrol and diesel engines, with four, six and eight cylinders and an output range of between 150 kW (204 hp) and 300 kW (408 hp), or 2143 to 4633 cc displacement.
A total of 12 different paint finishes, including the SHAPE manganite grey matt paintwork, can be combined with the five interior colours – black, alpaca grey, almond beige, aubergine and porcelain. Three different versions of leather upholstery are available to choose from: leather (nappa leather), PASSION leather (a fine semi-aniline leather) and Exclusive PASSION leather (where also the instrument panel and beltline are leather-covered). There are five different finishes available for the trim elements – brown high-gloss burr walnut, black high-gloss ash, satin-finish light brown poplar, black piano lacquer as well as AMG carbon fibre for the CLS Edition 1. In this way, customers purchasing a CLS can, according to their own tastes, choose to accentuate either fresh naturalness or elegant sportiness.
Countless optional extras make it possible to individualise one’s Mercedes-Benz CLS-Class further – including opting for active multicontour seats, LED High Performance headlamps, Keyless Go and the harman/kardon sound system, as well as many support systems including the new Active Blind Spot Assist and Active Lane Keeping Assist with brake actuation (for more information on the latter, please refer to the section “Active Safety”). Over and above this, Mercedes-Benz has put together three packages offering appropriate combinations of optional extras.
A customer opting for the Exterior Sports package will get a Mercedes CLS with visible, chromed tailpipes. The Sport CLS also has a lowered suspension with sports tuning, alloy wheels in size 18 or 19 (and, optionally, in anthracite) and a trim element in black on the rear bumper.
The AMG Sports package comprises a multifunction sports steering wheel in nappa leather in the 3-spoke design, with flattened bottom section, aluminium pedals, AMG bumpers to the front (with single-louvred grille) and rear, AMG alloy wheels in size 18 or 19, AMG floor mats, visible tailpipes, and in the interior, in combination with black leather seats, light-coloured felled seams on the seats, headrests and armrests. With the AMG Sports package, the automatic transmission has a third shift programme – M – which allows the gear to be selected manually using the paddles on the steering wheel. In addition to this, the adaptive suspension is more sportily tuned.
The Exclusive package combines seats in fine semi-aniline leather with nappa leather for the instrument panel, centre console and parts of the door trim. The roof lining is made of alcantara. The Exclusive package, which also includes ambient lighting, is available with all the interior colours and trim elements.
The CLS “Edition 1” will be available for a limited period of one year following market launch. The distinguishing features of this special model are the SHAPE matt paint finish in manganite grey; the leather upholstery in designo corteccia tundra brown pearl which has a metallic shimmer to it; floormats with Edition 1 lettering; a black roof liner; and aluminium pedals. For the interior trim elements in the Edition 1 there is a choice between satin-finish light brown poplar, black piano lacquer or AMG carbon fibre.
The bodywork: A first: frameless, all-aluminium doors
Intelligent lightweight construction plays a decisive role in bridging the classic conflict of objectives between low weight and high strength in the new CLS. The CLS is thus the first vehicle from Mercedes-Benz to have frameless, all-aluminium doors. These are made from deep-drawn aluminium panels with extruded sections, and in comparison with conventional steel doors, are some 24 kilograms lighter. This is not only beneficial to the environment, operating convenience is increased too: the Coupé doors can be opened and closed more easily, particularly on an incline. The new construction has called for new joining techniques: instead of welding, a combination of gluing and riveting has been used.
In order to assure quality, in the production process the doors are positioned in the frames by extremely precise robots; and the side windows are fitted with the greatest precision using laser measurement technology. As a result, this door design meets the same seal requirements as for the door frames on a saloon, which has to be demonstrated in a Mercedes internal test (one of several) in which it is subjected to high-pressure testing with water pressure at 80 bar. To put this in context: this pressure is about five times higher than the pressure needed by an espresso machine to produce a good crema.
Apart from the doors, the bonnet, front wings, boot lid, parcel shelf, various support profiles and substantial parts of the suspension and engines are all made of aluminium. The front end is a hybrid construction made of aluminium panels and plastic strengthened with fibre-glass. The one-piece aluminium crash boxes in the front area are fitted in the side members and are screwed into the side with them.
The large front bumper with the integral grille with the centred star is made of polypropylene. The materials experts at Mercedes-Benz have worked together with the experts from the supplier of this part to develop the plastics formulation, which has a specific talcum content of 15 percent, in order to achieve an optimum compromise between weight and rigidity, as well as excellent thermal properties. As supporting structure for the bumper there is a front end which is a hybrid construction of aluminium sheet and plastic strengthened with fibre glass. For every CLS, special adjustable fixtures are used to ensure the front fits exactly and the gap dimensions are the same all round.
About 72 percent of all panels used for the bodyshell of the new Mercedes-Benz CLS-Class are made from rigid and ultra-rigid steel alloys. The ultra-rigid high-tech alloys, which have three to four times more tensile strength than conventional rigid types of steel, account for around eight percent of total weight. They are deployed in areas in which there could be extreme material stresses in the event of an accident – for example, in the event of a side-on collision, in the B-pillars and side frame of the roof; as well as in the rear, to create a stable crossmember.
Front-end structure: crumple zone on four levels
Compared to the previous model series, the Mercedes engineers have further enlarged the deformation zones substantially in the front and rear sections of the new CLS, as well as improving the energy flows. The front crumple zone has four independently acting impact levels, meaning that the forces can be distributed over a wide area while bypassing the passenger cell.
- Sectional panelsabove the wheel arches form the upper side-member level. From here, the impact forces are channelled into the A-pillars and, subsequently, into the roof frame.
- An aluminium crossmember connects the forward-extended side members and ensures that the forces are transferred to the side facing away from the impact. The crossmember and the forward-extended side members form the central impact zone.
- The subframe to which the engine, steering and front axle are attached also serves as an impact level in the event of a frontal collision. It is made of high-strength steel and, depending on the engine variant, can be connected to the newly developed floor side members by means of special supporting tubes. As a consequence, the subframe can deform in a predetermined manner and absorb energy in the event of a crash on the one hand and channel high impact forces straight into the vehicle floor on the other.
- The side skirts have been extended forwards to support the wheel and prevent it from entering the footwell in the event of an offset frontal collision. In order to provide specifically targeted front-wheel support and location, Mercedes-Benz has also developed special struts and additional energy-absorbing elements for the wheel arches. The struts are arranged diagonally and prevent the passenger cell from sinking in the event of an impact.
The firewall is a four-part construction. This design enables Mercedes engineers to vary the material thickness according to the level of vulnerability in an accident. As the load acting on the firewall during a frontal crash is greatest in the lower section, the sheet steel used here is almost 50 percent thicker.
As well as being a major reason behind the high level of impact resistance, this intelligently designed bodyshell not only enhances ride comfort, it also reduces noise and vibration. The Sindelfingen engineers paid particular attention to the connecting points between the suspension and the bodyshell, which are required to withstand very high forces. These were specifically reinforced to ensure that road-induced vibrations are not transferred to the body at the expense of driving enjoyment. An indicator of the excellent overall result is the static flexural strength of the bodyshell, which shows a 28 percent improvement over its predecessor. Torsional strength increased by six percent.
Passenger cell: custom-designed floor panels and robust load-bearing sections
The passenger cell of the new CLS has been shown to be a structure which is virtually immune to deformation and which keeps the occupant space intact, even at high impact speeds, regardless of whether the collision is head-on, from the rear or from the side, or whether the vehicle rolls over. The use of high-strength steel and thicker panels plays as important a role here as the installation of additional load-bearing members.
The main floor assembly thus consists of different sheet-metal plates that either undergo flexible rolling or are welded together by laser beam and subsequently shaped. Flexible means that the high-tensile steel can be processed in such a way that areas with different steel thicknesses can be produced within a single component. The middle blank forms the tunnel – the actual backbone of the passenger cell. Here the thickness of the custom-designed panels varies between 0.7 and 1.1 millimetres, and between 1.55 and 2.0 millimetres for the tunnel reinforcements, depending on the stresses and loads to which they are subjected.
The continuous floor side members, the insides of which are further reinforced with extra sections, are very important both for occupant protection and the rigidity of the bodyshell. Their front faces connect to the side members, thereby lengthening the load-bearing paths along which forces can be distributed in the event of an impact. At the rear, the floor side members extend as far as the crossmember beneath the rear seat unit to stabilise the entire floor structure.
The Mercedes engineers have also incorporated sturdy aluminium transverse sections – known as transmission tunnel braces – into the floor assembly. One is located beneath the transmission, and is designed to direct forces to the side of the vehicle facing away from the impact in the event of a side-on collision. The second forms a connection between the two side members. It likewise braces the floor assembly and is able to channel impact forces into the floor structure at an early stage following a side-on collision.
Rear-end structure: side members with specifically graduated material thicknesses
Multi-piece side members and a robust, flexible crossmember made from ultra-high-strength steel form the key components of the rear-end structure. The rear side members are continuous, closed box sections with carefully graduated material thicknesses. These are able to absorb high forces, thereby making a decisive contribution to occupant safety in the event of a rear impact. The bolt-on flexible crossmember is manufactured using a flexible rolling process which likewise allows the material thickness to be varied as required. Accordingly, the material thickness on the outside of the crossmember – where impact loads are highest – is greater than on the inside.
Active safety: New assistance for drivers
Avoiding accidents and reducing the consequences of accidents: this is the comprehensive approach adopted by Mercedes-Benz in its safety research and referred to collectively by the company as “Real Life Safety”. As part of this, a variety of systems designed to reduce the burden on the driver even further will be making their debut in the new CLS. These include Active Blind Spot Assist and Active Lane Keeping Assist as well as LED High Performance headlamps offering various light functions. The new features represent a further improvement of so-called “driver-fitness safety” by the company’s engineers. In addition to ride and seating comfort and also quiet running, a significant role is also played by the headlamp and windscreen wiper systems, for example, as well as the easy, safe operation of the vehicle. On top of this there are also the PRE-SAFE systems which can warn, support and protect the driver when a real risk of an accident has been detected.
Premiere: LED High Performance headlamps with complete light functionality
The new CLS is the first car in the world to feature optional LED High Performance headlamps, which combine the exciting daylight colour impression of LED technology with the performance, functionality and energy efficiency of today’s bi-xenon light generation. The new light system features the Intelligent Light System which has already been tried and tested in Mercedes-Benz models with bi-xenon headlamps. Its five light functions – country mode, motorway mode, enhanced fog lamps, active light function and cornering light function – have been specifically designed for typical driving or weather conditions.
In contrast to the first vehicles equipped with LED headlamps, no compromises are now necessary with respect to the functionality and performance of the lighting technology. There are further arguments for the LED-based lighting technology: the average operating life of an LED is around 10,000 hours, around five times longer than that of a xenon light; moreover, LED headlamps most closely approximate to the colour of daylight. This means that LED light is in keeping with the normal human perception patterns. Studies have shown that the closer the colour of artificial light comes to daylight, the less the strain on the eyes. With a colour temperature of 5500 kelvin, LED light is closer to daylight (6500 K) than xenon light (4200 K). The driver’s experience of this effect is that colour impressions at night-time seem close to daylight colours and he or she has the feeling that there is greater brightness on the road.
The light specialists at Mercedes-Benz have also been able to combine LED technology with the innovative Adaptive Highbeam Assist for the first time, leading to a completely new level of safety at night. The basic principle behind Adaptive Highbeam Assist is as follows: if the system detects an oncoming vehicle or a vehicle in front with its lights on, the system dims the headlamps and continually adjusts the headlamp range in such a way that the cone-shaped beam of headlamp light does not reach these vehicles. There is, in addition, the Night View Assist Plus system as an option.
But good visibility is not only needed at night – and can also depend on a number of seemingly irrelevant factors. So that the CLS driver’s view when looking forward at an angle is not obscured – despite the angled coupé-like windscreen and A-pillars – the exterior mirrors are not mounted in the window triangle. Instead they have been given a new elevated position on the beltline. This improves all-round visibility, especially when turning into side streets, for example.
Premiere: Active Blind Spot Assist and Active Lane Keeping Assist
Assistance systems are becoming increasingly important these days, providing support for drivers as they perform a complex activity. In the new Mercedes CLS, for example, proven technologies like ABS, ESP®and Brake Assist work alongside a dozen assistance systems to help prevent accidents and reduce their impact. These range from drowsiness detection to automatic full brake application on recognising that there is an acute risk of a collision, and from Adaptive Highbeam Assist to traffic sign recognition.
One new feature is the Active Blind Spot Assist. It warns the driver when changing lanes if a risk of collision is detected due to another vehicle in the neighbouring lane being in the so-called blind spot of the exterior mirror. If the driver ignores the warning and nevertheless initiates the lane-changing manoeuvre, the Active Blind Spot Assist intervenes. By applying braking force to the wheels on the opposite side of the vehicle, a yaw movement is created which counteracts the collision course.
Active Lane Keeping Assistis now also linked to the ESP® for the first time. This system kicks into action if the Mercedes vehicle inadvertently drifts over a solid line to the right or left of a lane. In such a case, a warning sign in the instrument cluster and vibration of the steering wheel give the driver warning. If the driver does not heed the warning in the case of the solid line, Active Lane Keeping Assist can use the ESP® to brake the opposite wheels and thereby prevent the vehicle from crossing the solid line. You can read more about these two assist systems in the section “Under the Microscope: Assist Systems”.
Premiere: Active Parking Assist including PARKTRONIC
Active Parking Assist will answer the prayers of many drivers in the chronically congested traffic areas of Europe: the Mercedes-Benz CLS-Class can not only detect parking spaces, but also help with the parking itself. This is made possible thanks to a combination of the new electomechanical direct steering (see the section entitled “Suspension”) and a series of ultrasonic sensors. This convenience system features the following functions:
- Measurement of the length and depth of potential parking spaces at a vehicle speed of up to 36 km/h
- Calculation of a suitable parking course based on the current position of the vehicle
- Control of the steering in order to maintain this parking course.
Parking spaces are measured using two enhanced ultrasonic sensors integrated into the right and left sides of the front bumper. Depending on the speed and driving cycle, these sensors are used to measure parking spaces and also to support the PARKTRONIC functionality.
When driving at less than 30 km/h, a “P” symbol is displayed in the instrument cluster to inform the driver that the active parking space search function is enabled. If a parking space is found, an arrow appears next to the “P” symbol. By default the arrow indicates parking spaces on the front-passenger side. If the turn indicator is set to the driver’s side, parking spaces on the driver’s side will be displayed. It is not necessary to switch on the parking space search function. The ultrasonic sensors only carry out a geometric assessment of the potential parking space, and do not assess whether this free space is actually a parking space. Responsibility during the parking process also remains with the driver. If the ultrasonic sensors detect a pavement then the vehicle is parked parallel to this.
Automatic steering: this is how the parking process works
The Active Parking Assist parking process begins when the vehicle is in front of the parking space indicated by the arrow, facing the direction of travel, and the driver has engaged reverse gear and confirmed an appropriate warning dialogue with the system via the instrument cluster. The driver continues to control the accelerator and brake pedals whilst manoeuvring into the parking space. The Active Parking Assist takes over lateral guidance by controlling the electric steering in accordance with the longitudinal dynamics specified by the driver and the parking course.
The maximum speed of this parking process is limited to 10 km/h. If the speed reaches 7 km/h, a warning appears in the instrument cluster – “Parking Assist only functions up to 10 km/h” – accompanied by a warning tone. The familiar PARKTRONIC function can be used without any restrictions being imposed. The system switches off as soon as the driver intervenes in the automatic steering control process, switches off the system via the PTS (Parktronic Sensor) button, both the driver’s seat belt buckle is released and the driver’s door opened, or a system error occurs.
The entire PARKTRONIC and Active Parking Assist system comprises the following components:
- Control unit
- Ten ultrasonic sensors, two of which have an extended range
- PTS warning elements on the dashboard and in the roof lining at the rear
- PTS button
A maximum of five manoeuvres are allowed (backwards-forwards-backwards-forwards-backwards). The wheels are then straightened out again. The final parking manoeuvre is notified in the instrument cluster with the message “Parking Assist completed”, accompanied by a confirmation tone.
Wake up: ATTENTION ASSIST issues warning on detecting drowsiness
Studies have shown that around a quarter of all serious motorway accidents are caused by drowsy drivers, making this factor an even bigger cause of accidents than drink-driving. With ATTENTION ASSIST, fitted as standard in the new CLS, Mercedes-Benz is therefore making another important contribution towards helping to avoid accidents: it employs high-resolution sensors to observe driver behaviour and can recognise whether the driver is tired or not paying attention, based primarily on steering wheel movements.
The ATTENTION ASSIST system developed by Mercedes-Benz measures more than 70 parameters which are analysed to detect fatigue. This continual monitoring is important in order to recognise the gradual transition from alertness to tiredness and give the driver plenty of warning. Based on a variety of data, ATTENTION ASSIST creates an individual driver profile during the first few minutes of each journey and compares this with sensor data and the driving situation as recognised by the vehicle’s electronic control unit. Alongside values such as the steering behaviour of the driver, the Mercedes-Benz system also measures driving conditions such as speed, longitudinal/lateral acceleration, indicator and pedal usage, as well as external factors such as the unevenness of the roads, for example.
DISTRONIC PLUS: now with enhanced functions
The radar-based DISTRONIC PLUS proximity control supports the driver at speeds between zero and 200 km/h by automatically adjusting the distance to the vehicles in front. In doing so it is able to apply the brakes to bring the vehicle to a complete standstill and also accelerate it again. As a result, the system is also particularly convenient in stop-and-go traffic. If the system detects that the distance is being reduced too quickly, it warns the driver with both visual and audible signals.
With the introduction of the new generation of the CLS, the functionality of DISTRONIC PLUS has been enhanced even further. It now reacts earlier to vehicles which cut in, and the vehicle accelerates quicker when changing lanes itself and where the overtaking lane is clear. Thanks to the incorporation of information from digital maps (navigation mode), automatic control has also been further refined.
Additional assistance: from the ADAPTIVE BRAKE to the PRE-SAFE® Brake
- ADAPTIVE BRAKE: this Mercedes-Benz brake system offers assistance functions for greater safety and comfort, such as a HOLD function when waiting at traffic lights, and Hill-Start Assist which can help prevent rolling backwards when moving off on a slope.
- Adaptive Highbeam Assist:when vehicles are detected ahead of or oncoming to the vehicle, this system automatically dips the beams and adjusts the range of the headlamps appropriate to the distance.
- Brake Assist PLUS: this system is able to recognise an impending rear-end collision using radar sensors. It calculates the necessary degree of braking assistance and makes it available immediately when the driver presses the brake pedal.
- Headlamp Assist: a sensor on the windscreen detects the lighting conditions. As a result, the headlamps can be turned on automatically when darkness falls.
- Speed Limit Assist: a camera fitted behind the windscreen detects speed limit signs at the roadside and compares this data to information contained in the GPS system. The relevant speed limit is then displayed in the instrument cluster.
- Night View Assist PLUS: The display in the dashboard shows a realistic grey-scale image from an infrared camera that monitors the road ahead of the vehicle. Any pedestrians detected are additionally highlighted in the display with so-called photo corners.
- PARKTRONIC: ultrasonic sensors assist the driver when parking.
- PRE-SAFE® Brake: autonomous braking if acute danger of an accident is detected. At first the driver is given both an acoustic and an optical warning if the system identifies there is a danger of collision. If the driver does not react to this, the system brakes the vehicle autonomously. This occurs in two stages: around 1.6 seconds before the calculated impact point the system decelerates the car with around 40 percent (approx. four m/s²) of the maximum braking power, gives the driver an additional, haptic warning of the impending impact and as a precaution activates the reversible PRE-SAFE® occupant protection system. If the driver still fails to react, the PRE-SAFE® Brake activates the maximum braking power around 0.6 seconds before the now unavoidable collision – this emergency braking can greatly reduce the severity of the impact. The system therefore acts like an “electronic crumple zone”, offering the car occupants even greater protection. The PRE-SAFE® Brake is active at speeds of between 30 and 200 km/h when moving vehicles are detected in front of the car. The system also reacts if the car approaches a stationary queue of traffic, providing its speed is below 70 km/h.
Passive safety: Nine airbags as standard
Drivers of Mercedes vehicles are safer on the road than drivers of other car brands. This is the result of a study by Mercedes-Benz accident research based on official, anonymous data samples from the Federal Office of Statistics. Having looked at 18,748 accidents resulting in personal injury during the period from 2003 to 2007, the study found that the risk of being seriously or fatally injured as the driver of a Mercedes is 9.6 percent lower than for vehicles of other brands. The result represents clear evidence of the contribution made by the passive safety systems of Mercedes-Benz to reducing the consequences of an accident.
The main prerequisites for this include a stable body structure (see the section entitled “The Bodywork”) as well as a whole host of sophisticated restraint systems. With nine airbags fitted as standard, not to mention four seat-belt tensioners and belt-force limiters as well as NECK-PRO crash-responsive head restraints for the driver and front passenger, the new CLS offers an even more extensive package of safety equipment than the previous model. The airbags, which can deploy in a matter of milliseconds in the event of an accident, include two adaptive airbags for the driver and front passenger, a kneebag for the driver, two sidebags in the front-seat backrests and two large windowbags which extend from the A-pillar to the C-pillar during a side impact. For the first time, pelvisbags are included as standard for front seat passengers, which in the event of a side collision can help to reduce loads in the pelvic area. Sidebags are also available for the rear as an optional extra, which means that the new CLS makes a total of eleven airbags available for occupant protection.
Three-point automatic safety belts with belt tensioners and belt force limiters are fitted as standard for the driver, front passenger and rear passengers. Mercedes-Benz is offering adaptive belt force limiters for the rear seats as an option. These adapt to the size of passengers automatically. The system detects whether the rear seat passenger is large or small as soon as the seat belt is put on, based on the length of the pulled-out seat belt, and can adapt its protective effect accordingly. The maximum belt force is activated immediately if the rear passenger is large in size, while in the case of smaller occupants the force exerted by the belt is initially set to a lower level.
For the first time Mercedes-Benz is offering the CLS with ISOFIX, the international standard securing system for child seats. The mechanism is fitted as standard and comprises two retaining brackets in each rear seat position, in the gap between the back rest and seat cushion, as well as an additional third anchor point, the so-called top tether.
NECK-PRO is the name Mercedes-Benz has given to a crash-responsive head restraint whose development, like that of PRE-SAFE® and other Mercedes-Benz innovations, is based on analyses of real accidents. NECK-PRO is an effective means of reducing the risk of whiplash injuries during a rear-end collision. If the sensor system detects a rear-end collision with a defined impact severity, it releases pre-tensioned springs inside the head restraints, causing the head restraints to move forward by about 40 millimetres and upwards by 30 millimetres within a matter of milliseconds. This means that the heads of the driver and front passenger can be supported at an early stage.
The occupant protection system PRE-SAFE®: preventive measures reduce the consequences of an accident by up to 40 percent
In 2002 Mercedes-Benz became the first automotive brand to offer an anticipatory occupant protection system which can initiate measures to protect the occupants of the vehicle if there is an imminent risk of an accident: PRE-SAFE®. Mercedes-Benz’s intelligent approach takes its lead from nature: PRE-SAFE® activates protective measures for the car occupants as a precaution, just as living things react instinctively and search for cover when they are in danger. The aim is to prepare the occupants and vehicle for an imminent collision so that the seat belts and airbags are able to fulfil their protective function to the full during an impact. What’s more, the PRE-SAFE® protective measures are reversible: if the accident is averted, the advance tensioning of the seat belts is halted automatically and the occupants are able to reset the positions of the seats and the sliding sunroof. The anticipatory occupant protection system is then ready for action again straightaway.
Early accident detection is possible because PRE-SAFE® is an intelligent synergy of active and passive safety. It is linked to Brake Assist and the Electronic Stability Program (ESP®), whose sensors detect potentially critical driving situations and send the relevant information to the electronic control units within a matter of milliseconds.
The new Mercedes CLS is able to offer even more preventive measures ahead of an imminent accident than ever before:
- Whereas PRE-SAFE® previously responded to emergency or panic braking – in other words when the driver hit the brake pedal reflexively – the system in the new CLS can also be activated if the optional DISTRONIC PLUS has detected an impending collision with the aid of short and long-range sensors, and a certain level of delay in braking has been exceeded. The occupants are prepared for the collision by tensioning of the seat belts and repositioning of the front-passenger seat (if the seat memory function is installed) – which is also optionally available with fully electric seat adjustment – enabling the seat belts and airbags to offer the best possible protection.
- The active multicontour seat (optional extra), ensures that the driver and front passenger are seated even more securely, thereby limiting dangerous whiplash movements by the upper body in the event of an accident. If the PRE-SAFE® control unit detects a critical driving situation, it immediately activates the air chambers in the seat cushions and backrests. These then envelope the seat occupants and give them support.
- Tests at the Mercedes-Benz Technology Center have shown that this PRE-SAFE® function and preventive belt tensioning increases the distance between the shoulder and the inner door lining by up to 40 millimetres at a lateral acceleration of 0.6 g. This enables the sidebag to fulfil its protective function even more effectively.
PRE-SAFE® triggers the following anticipatory measures:
- PRE-SAFE® when braking in an emergency
- Driver and front-passenger seat belts are tensioned
- The seat fore-and-aft adjustment, and the cushion and backrest angles on the front passenger seat are moved to the best possible positions for crash conditions
- Bolsters in the seat cushions and backrests of the multicontour front seats can be inflated
- PRE-SAFE® if high lateral acceleration is detected
- The side windows can be closed
- The sliding sunroof can be closed
When installed in combination with DISTRONIC PLUS, PRE-SAFE® also uses the information provided by the short-range radar sensors in the front bumper to tension the front seat belts at the very last moment before an unavoidable collision, thus reducing the forces exerted on the driver and front passenger during the crash. This PRE-SAFE® function is literally the “ultima ratio” of anticipatory occupant protection, since the accident occurs around 200 milliseconds later.
The drive system: Four new engines giving the ultimate in driving pleasure
Efficiency at the highest level: this is the common characteristic shared by all four engines used in the Mercedes-Benz CLS-Class. All of the engines feature increased performance and torque compared with previous models, while at the same time boasting significantly reduced consumption and CO2 emission levels. The two V6 engines are typical examples: the diesel engine in the CLS 350 CDI BlueEFFICIENCY now offers an increase in output of 30 kW, yet at an average of 6.0 litres/100 km consumes 21 percent less fuel than its predecessor.
Thanks to third-generation BlueDIRECT injection technology, the V6 petrol engine in the CLS 350 BlueEFFICIENCY is 25 percent more economical than before, despite an increase in maximum output of 10 kW: it now consumes just 6.8 litres per 100 km and matches its diesel counterparts in terms of CO2 emissions at 159 g/100 km, making them the global role models in their performance class. Advances in efficiency which are every bit as impressive are also to be expected of the V8 engines. The CLS 500 BlueEFFICIENCY will become available during the course of the coming year. The CLS will also become available then with 4MATIC all-wheel drive for the first time.
Setting entirely new standards for efficiency in the luxury segment is the CLS 250 CDI BlueEFFICIENCY. Available for the first time in the four-door Coupé, the four-cylinder direct injection diesel engine has already enthralled customers of the E-Class. With an output of 150 kW (204 hp), a top speed of 242 km/h and a full 500 Nm of torque, it provides complete driving pleasure yet will astound you when filling up with its consumption figures comparable to those of a compact car: on average the CLS 250 CDI BlueEFFICIENCY uses 5.1 litres per 100 km, which is equal to CO2 emissions of 134 g/km.
In addition to optimisations in the powertrain – all CLS models are fitted with the enhanced 7G-TRONIC PLUS automatic transmission as standard – the sophisticated ECO start/stop system helps to ensure extreme efficiency even when driving in urban traffic. Like the petrol models in the CLS range, the CLS 250 CDI BlueEFFICIENCY is fitted with this system as standard.
The ultimate diesel: the V6 engine in the CLS 350 CDI
195 kW (265 hp) and 620 Nm of torque: the excellent diesel engine in the CLS 350 CDI BlueEFFICIENCY is now even more powerful and boasts a correspondingly superior performance. The Coupé accelerates to 100 km/h in 6.2 seconds, and has a top speed of 250 km/h. And despite the increase in output of 30 kW and the additional tractive power of 80 Nm, the V6 consumes a fifth less fuel than previously, at 6.0 litres per 100 km.
To achieve this, the Mercedes engineers have basically revised the engine. It now has improved engine management in the form of new-generation control units and new software, new sensors and actuators, and more efficient aftertreatment in the maintenance-free diesel particulate filter system with reduced back-pressure. In addition to more effective cooling of recirculated exhaust gas using a variable bypass valve, the in-engine measures include a reduction of the compression ratio from 17.7:1 to 15.5:1, an optimised VNT turbocharger with low-friction shaft bearings for greater agility and high output, new injection nozzles and revised ducting in the intake tract. A whole package of measures has resulted in substantial fuel savings: these include generally lower in-engine friction (through precision honing of the cylinder walls, amongst other measures), more efficient thermal management, an improved compound oil pump and modified cylinder head cooling. With an engine idling speed of 520 rpm, a new optimum value has also been achieved.
Petrol engine with BlueDIRECT: the most efficient form of direct injection
The second generation of direct petrol injection made its debut in the CLS 350 CGI introduced in 2006. The six cylinder unit was the world’s first petrol engine with piezo-electric direct injection and spray-guided combustion, and as such achieved a fuel saving of around ten percent compared with its predecessor with port injection.
Now the third generation of direct petrol injection is celebrating its world premiere, this time in the new CLS. Christened BlueDIRECT, this innovation is helping to establish the V-engines of Mercedes-Benz as the world benchmarks, enabling a further reduction of 20 percent in fuel consumption to be achieved solely through in-engine measures. The key data of the CLS 350 BlueEFFICIENCY include: 225 kW/306 hp (plus 10 kW), 370 Nm (plus 5 Nm), fuel consumption of 6.8 litres per 100 km (minus 2.3 litres). The CLS 350 BlueEFFICIENCY accelerates from 0 to 100 km/h in 6.1 seconds, and achieves a top speed of 250 km/h.
The V6 petrol engine with BlueDIRECT technology in the CLS 350 BlueEFFICIENCY differs from its predecessor in the following key areas:
- 60° cylinder angle and omission of balancer shaft
- Extended lean-burn operation, lean-burn system with load monitoring from pressure information, new combustion system operating modes
- Multi-spark ignition
- Resonance intake manifold
- Latest generation of piezo injectors
- Enhanced cooling circuit control and optimisation
- Enhanced oil circuit control and optimisation
- Increased output and torque
BlueDIRECT: third-generation direct injection
Direct petrol injection with spray-guided combustion, which Mercedes-Benz was the first car manufacturer to introduce in series production, has been developed further by the engineers into third-generation direct petrol injection with spray-guided combustion. The system pressure is now up to 200 bar and is variably optimised according to the engine’s characteristic map. Completely newly developed piezo-electric injectors allow up to five injections per power stroke for the best possible mixture formation, while multi-spark ignition helps to ensure reliable combustion of the mixture. Further details on direct injection can be found in the section “Under the microscope: lean-burn mixture”.
While the V6 unit is a naturally-aspirated engine, the new, technically similar V8 engine, which is due to be introduced during 2011 as the CLS 500 BlueEFFICIENCY, features biturbocharging for the first time, previously only seen in the 12-cylinder engine used in the S-Class. It too has direct injection but was designed for countries without sulphur-free fuel and is therefore run in a homogenous mode through the engine’s entire characteristic map. Despite a significantly smaller displacement (4633 cc; previously 5461 cc), the eight-cylinder unit made considerable gains in terms of output (300 kW/408 hp; previously 285 kW/388 hp) and torque (600 Nm; previously 530 Nm). At the same time consumption has been significantly reduced. It is expected to achieve a saving in the region of 25 percent. Further details on the new engine generation can be found in the section “Under the microscope: innovative engine technology”.
ECO start/stop function: significantly reduced consumption in urban traffic
When the car is at a standstill, the engine does not need to be running and therefore does not need to consume fuel. Recognition of this essentially simple fact is behind the ECO start/stop function, which is available for the first time in the Mercedes-Benz CLS-Class with the 7G-TRONIC PLUS automatic transmission. In order to implement the auto start and auto stop function with a very high level of comfort in a Mercedes-Benz, it has been necessary to develop complex control logistics and a series of new or modified components, such as a Hall sensor for the crankshaft and a high-output starter motor. That’s because Mercedes drivers should only really notice the forced breaks taken by the engine when they are at the filling station – thanks to consumption figures which are up to eight percent lower in urban traffic and five percent lower in the ECE consumption cycle. In the case of the CLS 250 CDI BlueEFFICIENCY, CLS 350 BlueEFFICIENCY and CLS 500 BlueEFFICIENCY models, the ECO start/stop system is fitted as standard. More details can be found in the section “Under the microscope: ECO start/stop function”.
Smaller tank, same range
Because the new Mercedes CLS models consume significantly less fuel, it has been possible to reduce the filling volume of the fuel tank in the four and six-cylinder models to 59 litres. The 80-litre tank comes as standard on all V8 engines, and is offered as an optional extra on all CLS variants with the 59-litre tank.
7G-TRONIC PLUS automatic transmission available for the first time with the four-cylinder diesel
All CLS models come with the 7G-TRONIC PLUS automatic transmission as standard, for which the torque converter and main transmission have been developed and improved further with regard to fuel consumption and comfort. The new generation of the torque converter provides an improved dynamic response, better durability and reduced noise and vibration levels thanks to a new hydraulic circuit, as well as enhanced dampers and torque converter housing. The extreme wheel-slip reduction of the torque converter housing, combined with larger mechanical damper de-coupling, helps to reduce consumption significantly. In addition, the gearshift program in ECO mode has been changed in favour of lower engine rpm at cruising speeds.
With friction-optimised bearings and gaskets, as well as a new automatic transmission oil (FE-ATF) with reduced viscosity combined with an enhanced additive package, the transmission itself also contributes towards reducing consumption. When the cooling limits are observed, the increased service life of the new oil results in new oil change intervals of every 125,000 kilometres (new) instead of once every 50,000 kilometres (old). The improved electrohydraulic assembly of the transmission and the new friction-reducing materials used on certain transmission parts, combined with optimised software, also lead to better shift quality.
The Mercedes-Benz CLS-Class will also be available with 4MATIC all-wheel drive for the first time in the autumn of 2011.
The suspension: Excellent dynamics without compromising on comfort
Supreme driving dynamics coupled with superlative ride comfort on long journeys were the terms of reference in developing the chassis for the new Coupé, whose design and functions are geared towards a stylish sportiness. To this end the chassis concept, which has already been excellently received by the trade press and the public in the new E-Class, has undergone a thorough revamp, adding a central new component: electromechanical power steering features in the new CLS as a world first in the upper vehicle segment. This pioneering innovation offers the engineers broad scope for new tuning options and will be introduced in a large number of Mercedes-Benz models in the coming years. In addition, this steering technology also makes an important contribution to the overall efficiency of the CLS: the steering assist function only requires energy when steering actually takes place, cutting fuel consumption by up to 0.3 litres/7 g compared to the previous model.
In the new steering system the steering gear and the supporting servo-motor form a single compact unit and are mounted as previously on an extremely rigid and low-weight integral support frame made of high-strength steel which is positioned in front of the wheel’s centre line. As previously, the steering gear is designed as a direct-steer system, which means that the steering ratio becomes noticeably more direct over the steering angle. This enhances the vehicle’s handling and agility substantially.
In combination with the sensors and the control unit the new steering system allows substantially greater degrees of freedom in configuring the forces which the driver is required to apply at the steering wheel in different driving situations – from parking to fast motorway driving. Active damping enhances the feeling of safety when driving straight ahead at high speed. The desired steering feel has been defined on the basis of an extensive study conducted by Mercedes’ driving dynamics engineers (see section “Under the microscope: the Mercedes-Benz steering feel”).
In addition to more precise steering and a more comfortable feel at the wheel, the new electric power steering – whose production costs are markedly higher than those for the hydraulic systems employed to date – offers a range of additional advantages. Power assistance remains available when the engine is stationary, for example – whereby a control algorithm ensures that the combustion engine is not prompted to start up in ECO start/stop mode when the driver merely plays with the steering wheel while the vehicle is at a standstill. The new steering system has also enabled implementation of the “Active Park Assist” automatic parking function (see section “Active safety”) and relieves the strain on the driver on road surfaces which slope away towards the kerb.
The new steering system also assists with braking on a surface with vastly varying grip (split friction surface). Sensors recognise the impending yaw (the vehicle starts to turn towards the side of the lane with more grip). Through the superposition of steering moment the driver receives an impulse to countersteer. If he or she acts on this signal, the steering moment is withdrawn. Series of tests conducted with drivers have shown that deploying the Steering Assist on split friction surfaces has improved the directional stability and shortened the braking time.
The new CLS Coupé comes with a mechanically length- and height-adjustable steering column as standard. A variant featuring electric length and height adjustment with easy entry function is optionally available as part of the Memory package. The mechanical and electric versions of the steering column are height-adjustable by +/- 25 mm from the steering wheel’s home position and length-adjustable by 15 mm towards the front and 35 mm towards the rear.
The suspension: a proven design in a new guise
As on the E-Class, the front suspension takes the form of a 3-link front axle with McPherson struts, which has been especially modified for the new CLS. The key feature of this modified suspension is two individual links (pulling strut and cross strut) in the lower link plane which are positioned at a steeper angle than on the E-Class, thus raising the roll centre to 90 mm. This results in enhanced anti-roll characteristics with the same anti-roll bar diameter and added negative camber on the outer wheel when cornering. This in turn provides for enhanced suspension comfort and enables higher lateral forces to be transmitted to the road surface. The stabiliser is connected to the suspension strut. The forward-sloping pulling strut is designed as a weight-optimised forged aluminium component, while the cross strut fitted in lateral direction is a weight-optimised forged steel component. The tie rod is defined as the third link, forming part of the rack-and-pinion steering system. The arrangement and design of the wheel control parts, and in particular the manner in which the lower A-arm is divided into two individual links, offer more favourable characteristics for the axle kinematics than the fixed A-arm. The kingpin inclination is closer to the wheel centre. This provides for large longitudinal force leverage, thus minimising sensitivity to tyre imbalances and fluctuations in braking force.
The principle of the lightweight independent multi-link rear suspension mounted on a subframe has been adopted on the CLS from the new E-Class, on account of its unparalleled wheel control qualities. All components have been modified in comparison to the suspension’s predecessor, for enhanced comfort and added driving dynamics. The new suspension has been designed specifically as a lightweight construction. Almost all wheel control parts are produced in aluminium, in order to reduce the unsprung masses. The axle’s kinematics and elastokinematics have been optimised for greater agility and contribute substantially to the vehicle’s enhanced comfort as a result of the new configuration and the attendant reduced forces. A further comfort measure is the use of an additional support for the front subframe bearing on the body, which leads to a marked increase in introduction rigidity, thereby addressing the problem of noise vibration harshness (NVH).
Suspension: selective damping as standard
The standard steel suspension of the Mercedes-Benz CLS-Class is equipped with a selective damping system. The shock absorbers adapt to the given driving situation, reducing the damping forces automatically during normal driving with minimal actuation of the shock absorbers and increasing them as necessary up to maximum level during dynamic cornering or evasive manoeuvres.
The spring struts on the front axle consist of cylindrical, lateral force compensating coils springs, dual-pipe shock absorbers and newly-developed three-phase head bearings. The front axle stabiliser is connected to the spring strut, which also assists actively in controlling the front wheels.
AIRMATIC: air suspension with continuously variable damping system
The optionally available AIRMATIC air suspension (standard for the CLS 500 BlueEFFICIENCY) is combined with an electronically controlled continuously variable damping system which controls each wheel individually. A total of seven sensors monitor the driving situation and body status and relay information to an electronic control unit which additionally processes information on vehicle speed, steering wheel angle, braking torque and engine torque to determine the ideal shock absorber characteristic. The system adjusts the damping force for each wheel individually according to the given road or driving conditions. The extremely fast damping adjustment enables high driving dynamics without compromising on comfort. In evasive manoeuvres, for example, the damping forces are adapted immediately to the vehicle’s driving dynamics. The driver is additionally able to alter the vehicle’s characteristic by means of the damping programme switch in a broad range extending from comfortable to sporty handling.
Automatic ride-height control is a feature of the AIRMATIC system. The level of the vehicle does not alter as a result of loading, ensuring that outstanding ride comfort is maintained when the vehicle is loaded. Lowering of the ride height at higher speeds reduces fuel consumption and enhances driving safety. The driver is additionally able to increase ground clearance on rough roads or on difficult upward slopes by pressing the level adjustment button.
The aerodynamic lift has been reduced considerably in comparison to the predecessor model, further enhancing braking stability at high speeds. The front-axle lift coefficient, which is crucial to driving stability at high vehicle speeds, is on a par with that of the previous Mercedes CLS.
Brakes: with Hill-Start Assist and brake drying function
With the ADAPTIVE BRAKE, the new CLS offers an innovative braking system incorporating additional assistance functions for even greater comfort and safety. One example of this is the practical HOLD function: after braking to a standstill, briefly pressing the brake pedal a little further is all that is required to activate this function. The car is then held by the brakes, even if the driver’s foot comes off the brake pedal. The HOLD function is deactivated automatically when the car moves off.
If the driver’s foot moves abruptly from the accelerator to the brake pedal before an emergency stop, the brake system increases the pressure in the brake lines and brings the pads into contact with the brake discs so that maximum braking power is available as soon as the driver hits the brake pedal. This priming of the brakes allows the system to assist the standard-fit Brake Assist system.
ADAPTIVE BRAKE also has safety benefits in the wet: the system briefly applies the brakes at regular intervals to wipe the film of water from the brake discs and ensure that the brakes are able to perform at their peak. The finely metered brake pulses are imperceptible to the driver. This automatic brake drying function is always activated when the windscreen wipers have been operating for a certain length of time.
Finally, ADAPTIVE BRAKE assists the driver when starting on an uphill slope. When the sensors detect that the Coupé is stopped on an uphill slope, Hill-Start Assist is activated automatically, briefly holding the brake pressure at a constant level so as to prevent the car from rolling backwards.
Even more effective brake discs and brake booster
The brake system helps to reduce the unsprung masses through the use of floating (four- and six-cylinder models) or fixed front callipers with housings in aluminium or aluminium composite design and rear floating callipers with aluminium housings. Large front and rear brake discs provide an ideal technical basis for ensuring safe and reliable deceleration in any driving situation. The front and rear discs measure up to 360 millimetres and 320 millimetres in diameter respectively, depending on the engine version. To cool the brakes the Mercedes engineers have developed two-piece aluminium cover plates which have undergone testing in the wind tunnel. These ensure that the cooling air flows from the underbody into the wheel arches and subsequently on to the brake discs while the vehicle is in motion.
Wheels and tyres: 19-inch size available ex-factory for the first time
The four- and six-cylinder variants of the CLS feature 17-inch wheels fitted with 245/45 R 17 tyres as standard. The CLS 500 BlueEFFICIENCY is factory-fitted with 18-inch wheels and tyres in size 255/40 R 18 – this combination is available as an option for four- and six-cylinder models. Alternatively, 18-inch wheels fitted with tyres in size 255/40 R 18 at the front and 285/35 R 18 at the rear are available for all models. The 19-inch wheels which are available for the first time lend the Mercedes-Benz CLS-Class an even sportier appearance. These wheels are fitted with tyres in size 255/35 R 19 at the front and 285/30 R 19 at the rear.
The electronic stability programme which features as standard also monitors the tyre pressure and displays a warning in case of any sudden loss of pressure in a tyre. For this purpose the system continuously compares the rotational speeds of the wheels, which are primarily dependent on the vehicle’s speed, the load and the tyre pressure. The control unit additionally refers to other driving dynamics-related ESP® sensor signals, such as lateral acceleration, yaw rate and wheel torques, in order to diagnose pressure loss in a tyre. In this way the system is able to establish any deviations, informing the driver accordingly on the central display.