- Mercedes-Benz CLS550, 2012
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.
Other 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.
The interior: Luxurious surrounds with many exclusive touches
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:
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.
Other 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.
The interior: Luxurious surrounds with many exclusive touches
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.