2006 Mercedes-Benz CLS500

A Fresh New Market Segment

The CLS represents an entirely new class of Mercedes-Benz, bringing to ten the number of Mercedes-Benz model families marketed in Canada.  Defining yet another fresh new market segment in an ever-expanding and highly competitive auto industry, the CLS also represents the first four-door vehicle to combine the emotional appeal and dynamic design of a coupe with the comfort and functionality of a sedan.  Sometimes called a "four-door coupe," the CLS is arguably the most eye-catching Mercedes-Benz in the line-up.

From the standpoint of platform engineering, the new CLS shares much of its mechanical underpinnings with the E-Class sedan, although every body panel on the CLS is unique to the car.  In a sense, the CLS joins the S-Class-based CL coupe and the C-Class derived CLK to form a family of Mercedes-Benz coupes that make efficient use of existing chassis and powertrain layouts but clearly exhibit separate and distinct identities.

A Rich Heritage

Coupe models have figured prominently in the company's rich heritage of styling icons.  First, of course, is the 300SL "Gullwing" of the mid-1950s, but this legendary car was preceded by at least three coupe models – the 1936 Type 380 and only a year later, the immortal 540K, as well as the elegant 300S of the early 1950s.

Several four-door cars of the 1930s had noticeably "coupe-like" lines and are considered by some to be CLS ancestors – namely the long-wheelbase 200 and 290 "Streamliners." Starting with the 220S "Ponton" in 1956, a procession of gorgeous Mercedes-Benz coupes based on early E-Class and S-Class sedans graced the next several decades.  Collectively, these cars set the stage for the emergence of distinct coupe classes such as the CLK and the larger CL-Class.

2005 Market Launch in Canada

The Mercedes-Benz CLS500 arrived at dealerships across Canada during the first quarter of 2005, powered by a 302-horspower, five-litre V8 engine and a seven-speed automatic transmission that together provide 0-to-100 km/h acceleration of about 6.1 seconds.

Standard Airmatic air suspension provides an ideal combination of comfort and sporty suspension tuning, because it uses computer control to continuously and automatically optimize the car for both types of driving. 

The electro-hydraulic braking system that debuted on the Mercedes-Benz SL roadsters in early 2003 is also standard on the new CLS.  The new system controls brake pressure at each wheel individually in response to driving and road conditions.  Of course, a full array of Mercedes-Benz safety technology includes ABS anti-lock brakes with Brake Assist, traction control and the Electronic Stability Program (ESP). 

Even More Power and Grace for a Graceful CLS

Soon after the launch of the CLS500, a high-performance CLS55 AMG arrived with a supercharged 5.5-litre V8 that makes 469 horsepower and 516 lb.-ft of torque.  AMG, the high-performance division of Mercedes-Benz, has worked its magic on the CLS power train as well as its exterior and interior, including AMG sport seats with exclusive Nappa leather.  The CLS55 AMG can be identified by deeper front and rear aprons, sculpted door sills and staggered-width 19-inch AMG five-spoke wheels.  Ride height of the CLS55 AMG is nearly 13 mm lower, and for flatter cornering, its Airmatic springs, shocks and stabilizer bars are enhanced for high-performance driving.

DESIGN

Sweeping Lines and High-Tension Forms

The elegant design of the CLS is characterized by a sleek, sweeping silhouette – a timeless coupe form – that emphasizes a look of energy and power.  At the same time, its graceful roofline flows into the C-pillar to form a dramatic arch that spans the entire body.  Subtle interplay between taut lines and naturally rounded forms – a hallmark of modern Mercedes-Benz design – is highlighted on the CLS by its pronounced wedge profile, muscular front fenders and overhangs at the front and rear that elongate the contours of its sophisticated new shape.

Aerodynamics

The CLS500 slips through the air with little resistance, thanks to a drag coefficient of 0.30, attributable not only to a sleek body shape but also special underbody paneling, integrated wheel arch spoilers, a subtle spoiler molded into the edge of the trunk lid and close attention to the front wheel opening shape. 

While the wheels of a test car remain static in most wind tunnels, Mercedes-Benz uses two conveyor belts to drive the wheels, allowing engineers to study the real-world influence of turning wheels on drag and lift forces.  Their findings influenced the shape and structure of the underfloor paneling and the wheel spoilers.

Seeing In The Rain

Attention to aerodynamic efficiency also yields gains for wet-weather visibility.  Aluminium channels in the A-pillars help direct rain from the windshield onto the roof, where it flows into a drainage channel between the roof and the rear window weatherstrip.  The exterior mirror housings likewise manage rainwater, routing it downward at a flat angle and into the oncoming airstream.

The driver's side windshield wiper has a fixed axis of rotation, while the passenger-side wiper follows an eccentric sweep that enables it to clear an even larger area. 

Instead of the articulated joints used on conventional wiper blades, the Mercedes-Benz aero wipers consist of a one-piece blade with integral leaf springs and an aero spoiler.  This new design provides better wiping, less wind resistance and a reduced tendency to ice up in cold weather.

A standard rain sensor located on the windshield regulates the windshield wipers depending on the intensity of the rain.  When the wipers are turned off, both wiper arms lie on a ledge on the passenger side that is heated via a special air duct in the dashboard.  Wiper heating is activated whenever the heating or the air conditioning is set to defrost.  The windshield washing system features two twin-jet water nozzles that are electrically heated.

High-Tech Lighting

Projector-type halogen headlights behind polycarbonate lenses require less space than conventional lights, which gave the designers more latitude in the shaping of the CLS front end.  At the same time, these lights produce wide, even illumination of the road ahead, with a range of around 140 metres.

Optional bi-xenon high-intensity gas-discharge headlights (HID) – which employ a shutter to switch the xenon bulb from low beam to high beam function – provide drivers with an extra margin of night visibility.  The bi-xenon headlights are self-leveling to ensure proper aim, even when the car pitches during braking or acceleration, and regardless of vehicle loading.  The package also includes a high-pressure jet wash that cleans the lenses at the touch of a button.

Lights That See Around Corners

The optional bi-xenon lights feature new active-curve technology as well, in which the headlights actually turn slightly with the steering wheel to light up each approaching curve.  Adapting its response to vehicle speed as well, this feature, in comparison to fixed halogen lights, improves road illumination in turns by 90 percent! 

In addition, this package includes fog lights that double as cornering lights, which turn on below about 40 km/h when the headlights are on and the turn signal is operated, or the steering wheel is turned.           

Each cornering light illuminates one side of the vehicle to an angle of about 65 degrees and a distance of up to 12 metres.  These lights are designed to fade in and out, giving the human eye time to adjust!

Mercedes-Benz engineers put a great emphasis on the role that lighting plays in overall safety.  Several other measures to ensure proper lighting include:

• Emergency lighting: If a data line or electronic control module malfunctions, a pre-programmed circuit prevents the total failure of the vehicle's lighting systems.

• Fail-safe lighting: If a bulb that is important to the vehicle’s operating safety should fail, the   electronic unit will switch on other bulbs.

• Daytime driving lights

• Headlight switch-off delay: allows the driver to set “walk away” lights for up to 60 seconds after leaving the vehicle.

• Locator lighting: helps the driver find the car more easily.  When the CLS is unlocked in dark conditions using the remote control, the parking lights, taillights, license plate lamp and front fog lamps will come on for up to 40 seconds.  The driver can program this feature using the multifunction steering wheel and the main instrument cluster display.

INTERIOR

Those sweeping exterior lines continue right into the CLS interior, even visually linking the dash and the doors to the rear of the vehicle.  The centre console and transmission tunnel merge toward the rear, deftly dividing the two rear seats.  Leather and wood cover most of the interior surfaces, with natural-grain leather and matte-finish burl walnut trimming the dash.  Looking through the four-spoke steering wheel, three chronometre-type gauges and two LCD bar graphs in the instrument cluster are accented by chrome rings. 

Large rear doors are by far the most striking feature of the new coupe-like model.  The rear doors represent tangible added value that complements its spacious rear seating area.  The CLS boasts 829 mm of space between the front and rear seats, and what's more, the CLS trunk can hold 450 litres of cargo – more than any coupe and better than many sedans. 

Flowing Lines from the Outside In

The flowing lines of the dashboard are complemented by its surface, made from a soft-touch polyurethane skin sprayed onto the base material to provide a luxurious feel and high-quality appearance.  This production technique enables a smoother integration of such elements as air outlets into the surface and eliminates unattractive panel seams.  Even the passenger-side front air bag cover has an invisible seam. 

The dashboard itself has a sound-dampening design and is insulated at the front to prevent engine noise from entering the passenger compartment.  Even the cable and wire openings between the interior and the engine compartment have airtight seals to eliminate so-called sound bridges.

A magnesium cross member forms a strong anchor for the dashboard and its components. The radio, automatic climate control, instrument cluster and steering column are all attached to this solid structure, which both minimizes vibrations and helps achieve low noise levels inside the new CLS.

Cockpit Design With Diffuse Lighting

The cockpit-style instrument panel includes a speedometre in the centre, flanked on the right by the tachometre and on the left by an analog clock.  Vertical electronic bar graphs for fuel level and coolant temperature provide super-accurate readings for these functions. 

Warning lights are positioned within the driver's field of vision at logical locations, not just grouped together.  For example, the low fuel warning light is next to the fuel gauge, the coolant warning light next to the temperature gauge.

Lights encircling the front and rear overhead control panels provide six driver-selectable levels of interior lighting.  A nightlight at the rear can be dimmed using two buttons in the overhead control panel.

The sweeping console groups many of the car's controls for easy reach, including audio system and climate control, heated seats, optional power rear sun shade and optional Parktronic parking assist. 

The centre console features a flip-up switch panel. At the touch of a button, the panel of switches glides upwards, powered by mini electric motors, allowing occupants to access a storage compartment or optional six-disc CD changer located behind it.  About 30 seconds after it is opened or after a button was last pressed on the CD changer, the panel automatically closes.

Located on this switch panel are illuminated switches for central locking, ESP®, hazard lights, seat heating, rear head restraints, optional active ventilated front seats, and an optional rear-window sun shade.  The switches remain fully functional even when the switch panel is flipped up.

Multifunction Display

A power-adjustable steering wheel provides the driver with illuminated rocker buttons that are a great way to control many of the car's comfort and convenience features.  Two rockers with eight detents can access and adjust more than 50 different functions: trip odometers and trip computer with fuel tank range; audio system (station seek, CD track and volume); recall messages for vehicle diagnostics; clock; interior light dimming; language.

The wheel-mounted rocker switches and the multifunction display in the centre of the speedometer allow the driver to scroll forward or back between a number of "windows" and sub-menus within each window.  The display can show a selected radio station, and if equipped a personal phone book or even navigation instructions.  It can also flash up details of technical faults and, if required, instructions on how to proceed, all in plain-text form.

An optional voice control system operates both the major telephone functions and the audio system.  All it takes is a couple of words from the driver, and the car radio will automatically search for another station, skip to a new track on the CD or switch to navigation mode.

First-Class Seating

Standard 10-way adjustable power seats incorporate a suspension design for greater comfort.  The seat frame consists of an aluminium suspension base supported by a hinge at the front for adjusting the angle, and by two small coil springs at the rear.  Along with foam cushions inside the aluminium shells, this design enables the seat base to swing on the frame and become part of the suspension and shock-absorbing system.

The familiar Mercedes-Benz pictogram seat controls are conveniently located on the door panel.  Seat positions can then be stored in memory (for up to three people), which also stores steering wheel and exterior mirror position.  Using the keys that come with the car, different drivers can program their own specific settings.  The system provides an added convenience when exiting the car – when the SmartKey is removed, the steering wheel automatically moves upward and the seat moves rearward to provide more room for exiting.   Both the seat and the steering wheel return to their original positions as the driver is seated and the SmartKey is inserted. 

Heated, Ventilated Seats and More

In addition to the standard heated front seats, the new CLS offers active ventilated seats, an option first introduced in the S-Class.  Five mini fans inside each of the front seats draw air from the footwell – cool air in the summer and warm air in the winter. 

Air passes through special plastic ducting and permeable fabric to flow evenly from the perforated leather seat upholstery so that seats heated by the summer sun can cool down fast.  The airflow can be adjusted to one of three speeds.

A Spa Treatment on the Run

Optional multicontour seats house four individually inflatable air cushions.  In addition to infinitely variable lumbar and lateral support, these seats include individually adjustable thigh support.

Pressing the "Pulse" button begins a massage function.  Two air cushions in the lower lumbar region switch between medium and high air pressure in a programmed sequence that lasts five minutes and can be repeated as desired.

Four-Zone Climate Control

Four-zone climate control regulates temperature separately for each front and rear seat.  Each occupant can set their own preferred air temperature.  The rear passengers have their own digital control panel (at the rear of the front centre console) for setting a desired temperature and adjusting airflow.  Twelve electric motors ensure proper air distribution.  The system also registers the degree of sunlight and automatically adjusts temperature and airflow settings accordingly to maintain the preferred settings at each seat.

A multifunction sensor monitors humidity and pollutant levels in the ambient air.  If nitrogen oxide and carbon monoxide levels in the air exceed a certain threshold, the climate control system automatically switches over to air recirculation mode when using the activated charcoal filter.

Enhanced COMAND

The COMAND system features a large 16.5 cm (6.5-inch) TFT colour display screen and one set of easy-to-use controls for the audio system (includes AM/FM/weatherband/CD), optional integrated phone and optional GPS satellite navigation.  The navigation computer uses its own separate DVD player to hold the map database disc.

The standard high-performance digital audio system plays through 10 speakers – four lower mid-range speakers in the doors, two tweeters in the mirror triangles, two additional tweeters in the rear doors, one subwoofer in the parcel shelf, plus a centre-fill speaker in the centre of the dashboard.

Surround Sound On Wheels

An optional harman/kardon Logic 7 digital surround sound system provides an even more luxurious listening experience.  The system converts every conventional stereo signal from the radio and CD player into surround sound with seven output channels, offering audio perfection for passengers, regardless of where they are sitting.  The sound system includes a digital signal processor, has a total output of 480 watts and plays through 12 high-end speakers, including two speakers on the rear parcel shelf that produce the surround effect.  The system even changes volume automatically to compensate for ambient driving noise.

Distronic Cruise Control

Distronic adaptive cruise control helps automatically maintain a preset distance behind a moving vehicle in front with the help of a radar sensor.  In addition to varying accelerator pedal position like conventional cruise control, the optional Distronic system can also apply partial braking automatically if needed (up to 20 percent of maximum braking force), to maintain the desired following distance.   

The system is activated just like the standard conventional cruise control, by tipping the stalk above the turn signal.  By using the menu button on the multifunction steering wheel, the driver can choose to monitor a Distronic pictogram within the display in the centre of the speedometer showing the relative proximity of the car in front.

A thumbwheel on the centre console can adjust following distance to the vehicle ahead – by scrolling the thumbwheel forward, the driver reduces the following distance, and by scrolling rearward, increases following distance.

Keyless Go

With the optional Keyless Go system, several transceiver antennas in the car sense the presence of the SmartKey fob.  As long as the driver has the fob in a pocket or bag, gently pulling one of the door handles unlocks the car. 

The driver starts the car by depressing the brake pedal and touching a button on top of the gearshift.  Keyless Go also makes it impossible to lock the keys in the trunk.  If the keys are dropped into the trunk and the lid closed, the lid will automatically pop open in a few seconds.

Parktronic

Parktronic uses a series of sonar-type sensors in the front and rear bumpers to detect obstacles in the system's field of view.  The optional system provides audible warnings and displays the proximity of obstacles using bar graph displays – one on the centre dashboard for the front and another for the rear that's visible in the rear-view mirror.

Electronic Trunk Closer

The CLS offers an optional remote electronic trunk closer.  Pressing a button on the driver's door or the remote control opens the trunk lid gently by means of an electric motor and two springs.  Pressing a button on the inside of the lid or on the driver's door pulls the lid downward.  A servo locking mechanism then latches the lid completely.  As a safety precaution, the lid is designed to stop closing if a light force is applied before it latches. 

Run-Flat Tires with Pressure Loss Warning System

For the first time on a Canadian market Mercedes-Benz, optional run-flat tires will be available for the CLS500.  The special tires have self-supporting side walls that enable customers to continue their journey for up to 95 kilometres at about 90 km/h with a deflated tire.  Packaged with the run-flat tires is a tire-pressure loss warning system that uses the ESP system to measure wheel speed.  Since an under-inflated tire rotates faster, the system calculates whether there is a sudden loss in tire pressure. 

BODY

The design of the new CLS body structure ensures that occupants benefit from industry leading impact protection, super-responsive road holding and impressively low noise and vibration levels.

Mercedes-Benz engineers followed the principle of "the right material in the right place" in designing the new CLS, using aluminium only for those areas where it held the greatest weight-reducing benefit compared to steel.  Aluminium components include the front and rear subframes as well as the rear parcel shelf and partition behind the rear seat.

All other components in the bodyshell are made from sheet steel.  Various underfloor components as well as the reinforcements used around the bumpers and springs are made from a new grade of high-strength steel with a special dual-phase microstructure that helps it withstand extremely high loads.  The spare tire well is made from plastic. 

Many of the bodyshell panels are machined so that "low-stress joining" can ensure precision fitting.  Flanges around the borders of the steel parts are formed in such a way that any tolerances are balanced out as soon as the panels are placed together, allowing bodywork components to be welded to one another under low-stress conditions.  Rear side members, the bulkhead crossmember, the rear wall of the passenger cell and the parcel shelf all employ this sophisticated manufacturing process.

Manufacturing Processes Ensure High Strength

Mercedes-Benz employs several different manufacturing processes to add strength to the body structure without adding excess weight.  The main floor assembly consists of three different tailored blanks, which are laser-welded together and then precision fitted.  The middle of the three blanks is a thick (1.0 millimetre) panel forming the transmission tunnel, the sturdy backbone of the passenger cell.

A "flexible rolling" technique is used for making the two connecting members – which extend the front side members back into the structure of the floor assembly – to give them the required material thickness and strength.  In this process, high-strength steel can be machined at the rolling plant in such a way that a single component can contain varying panel thickness.

As an example, the front of the connecting members, where the loads exerted in a frontal collision are greatest, is made thicker (1.15 millimetres) than the rear section (0.88 millimetres), which is not subject to such high loads.  Impact energy flows more smoothly through a component made with this process, compared to using a number of different, pre-fabricated panel blanks joined together.

In addition to the two flexibly rolled connecting members, the body structure features a solid cross member running under the front seats, a load-bearing section between the B-pillars and reinforcement paneling in the footwells.

Corrosion Protection

Precision fitting of the bodywork components, low-stress joining technology and state-of-the-art spot and laser welding methods used for assembly of the bodyshell all combine to further enhance corrosion prevention. These assembly techniques nearly eliminate the need for extra soldering joints and MAG (metal active gas) welding seams at the panel joints, which used to be particularly susceptible to rusting.

By lining the entire underbody of the vehicle with a total of 11 plastic panels – which also enhance aerodynamic performance – Mercedes-Benz engineers were able to omit the conventional PVC underbody protection in the new CLS while still providing long-term corrosion prevention.  These panels cover the engine compartment, wheel arches, outer floor panels and rear axle links, effectively helping to protect the under-body from stone chips that could lead to rust.

Safety

Mercedes-Benz engineers have long studied real-world accidents and applied the knowledge gained to improve safety in new vehicle designs. The new CLS benefits from this approach by virtue of an extremely strong body structure and advanced restraint systems.

Crumple zones at the front and rear of the new CLS are designed to absorb and effectively redirect some of the impact energy.  The front subframe, to which components from the front suspension, steering system and engine suspension are attached, is an integral part of the front crumple zone.

Two-piece lower control arms that are part of the front suspension also help absorb impact forces, since the area between the two links can serve as part of the crumple zone.  In general, high-strength components – which include some made from super-strong, dual-phase steel – provide high strength with relatively light weight.

Replaceable Crash Boxes

The CLS absorbs crash energy in several ways.  In impacts below 4 km/h, flexible bumper covers are designed to deform but then return to their original shape, and an aluminium crossmember behind the bumper redirects some of the energy to the side that's not subject to direct load.

Second, aluminium cross members behind the bumpers attach to "crash boxes" (aluminium in the front and steel at the rear) that absorb crash energy, helping to protect the supporting structure.  Bolt-on connections make the front and rear crash boxes easier to replace after a low-speed impact, eliminating the need for straightening, welding and repainting.  Even the individual components contained within the modules are bolted together.

At higher impact speeds, reinforced front and rear side members in the bodyshell use a continuous closed box section with carefully graduated material thickness to help absorb high impact energy.  At the rear, a plastic fuel tank is located under the back seat where it is well protected from impacts.

Designed for Offset Impacts

The new CLS features a continuous crossmember that connects both sides of the bulkhead.  To help protect the passenger cell, this design distributes some of the forces of a frontal offset impact over a broad area into the transmission tunnel and the side members.  A vertical reinforcement further increases the strength of the bulkhead and, to help prevent foot injuries, limits movement of the pedals toward the passenger compartment in a severe frontal collision.

Lots of High-Strength Steel

Although the sidewalls of the CLS form a single section, they are made up of a number of panels that are laser-welded together and then pressed into the desired shape.  A steel tube in each B-pillar reinforces the roof and helps to support the passenger cell in the event of a rollover.  High-strength steel is used for the inner door shells, and each door incorporates a side-impact beam made from high-strength cold-formed steel.

The high-strength door hinge mounting plates are welded to the inner door shells.  The result is an integrated side structure that provides effective protection in the event of a side impact.

Intelligent Restraint Systems

The adaptive restraint systems in the new CLS optimize deployment of the seatbelt and the air bag systems, depending on the type and severity of an impact.  The CLS is equipped with ten-way protection from eight air bags – two in front, one side impact air bag for each passenger and a window curtain air bag on each side that protects both the front and rear occupants.

All four seating positions in the new CLS are fitted with three-point inertia-reel seat belts and belt tensioners.  In a collision, the tensioners take up seat belt slack quickly to increase the effectiveness of the belts.  Milliseconds later, a belt force limiter allows some give in the belt to soften peak forces and help reduce the risk of belt-related chest injuries.

The adaptive air bag system employs a central crash sensor as well as upfront sensors on the radiator cross members.  This design allows earlier detection of frontal collisions, and new control algorithms help to ensure that deployment of the air bags and belt tensioners is adapted even more closely to suit actual situations.  These measures help protect occupants in serious collisions and at the same time optimize protection in moderate collisions.  The electronic control module uses information from the front-mounted sensors to:

• Get more information earlier in the crash sequence about the nature of the impact.
• Trigger the driver's and front-passenger air bags not only more precisely but also in two stages, depending on the type of collision (see below).

Two-Stage Front Air Bags

The front air bags for the driver and front passenger deploy in two stages, depending on the impact severity and occupant size.  If sensors detect a minor front-end impact, only one chamber of the gas generator is deployed, so the bag is not filled as fully or as quickly as it is in a severe front impact.  In a more severe collision, the second chamber is deployed 5 to 15 milliseconds later.

Accident research indicates that this adaptive air bag control is especially beneficial in low-force collisions (usually between 19-35 km/h), as the first air bag deployment stage allows occupants to be cushioned more softly.

The new CLS considers the size of the front-seat passenger when deploying the front-passenger air bag.  A special electronic measuring pad in the seat upholstery automatically assigns the front-seat passenger to one of two size categories.  The air bag can then, for example, trigger both stages even in low-impact collisions to provide heavier front passengers an optimal level of protection.  The second air bag stage will only be deployed for lighter passengers, on the other hand, once a higher severity threshold is reached.

To help reduce repair costs, a sensor also monitors whether the front passenger seat is occupied, automatically deactivating the front passenger air bag and side impact air bag when the seat is unoccupied.

Two Types of Side Air Bags
The side impact air bags in the new CLS are housed in the backrests of the front seats, while the side impact air bags in the rear are located in the door trim.  In a side impact, those air bags inflate within a few split seconds to cushion the area between the occupant and the door.  The side impact air bags have an inflated volume of ten litres.

While side air bags are designed to help protect against torso injury, additional curtain or window air bags can help protect the head and neck, so that one system complements the other.  The window curtain air bags are positioned behind the trim panels for the roof frame and the A and C-pillars.  The air cushions on either side inflate within just 25 milliseconds and remain fully inflated for several seconds following the collision, in case of multiple impacts or a rollover.

Rollover Protection

The new CLS is equipped with a rollover sensor that can signal the central control module to deploy the window curtain air bags and belt tensioners if it detects this type of accident.  The sensor is positioned on the transmission tunnel, and inside its casing is a metal rod that responds to electrical input and vibrates in a similar fashion to a tuning fork.  The Coriolis force (force of inertia in a rotating system) that acts when the vehicle rolls over alters the frequency of the "tuning fork."  The microcomputer senses this change and instantaneously activates the protective systems.  The new CLS accommodates child seats with the standardized LATCH system (Lower Anchors and Tethers for Children).

Chassis

The new CLS features Airmatic DC fully independent suspension design and technology.  In front are double control arms with lower spring links, upper wishbones and torque struts.  The Mercedes-Benz-patented five-link rear suspension design, refined for this application, is adapted in aluminium.

The CLS boasts large vented disc brakes all around (330 mm diametre in front, 300 mm rear), with four-piston fixed calipers in front and single-piston floating calipers at the rear.  The CLS has staggered-width wheels and tires – 18 x 8.5-inch wheels with 245/40 R18 tires up front and 18 x 9.5-inch wheels with 275/35 R18 tires in the rear.

Rack and Pinion Steering

The new CLS is equipped with power-assisted rack-and-pinion steering that's only 2.8 turns lock-to-lock.  Speed-sensitive steering increases power assist at low speeds for easier maneuvering and parking, while reducing it at higher speeds for improved steering precision and feedback.

Computer-Controlled Air Suspension

Standard on the CLS is an Airmatic DC (Dual Control) air suspension system, which is paired with an adaptive damping system (ADS II) to provide simultaneous computer-controlled springing and damping.

Instead of conventional steel-coil springs, Airmatic DC uses compressed air in special rubber bellows in the spring struts.  When the vehicle is in motion, an electric air compressor charges the struts with compressed air via fast-acting solenoid valves (the compressed air having first been dried and purified by means of paper filters). The solenoid valves regulate air volume, hence air pressure and spring rate. A charge valve combines a central pressure sensor and the connectors for the pneumatic lines, which are made from polyamide plastic.

At low speed or at a standstill, the system draws on pressure from the accumulator (central reservoir) with a charging pressure of 227 psi (16 bar) to ensure rapid and noise-free ride height control.

Comfort and Sport Suspension In One

In short, the new Airmatic DC system offers a sports suspension and comfort suspension in one.  The system's adaptability solves the suspension tuning conflict between comfort and high dynamic handling by adjusting the springing and damping rates in response to driving input and road conditions.

Under normal driving conditions, the entire air volume remains active to provide optimal comfort, as with soft-rate conventional springs.  When cornering at speed, however, or where other dynamic handling requirements are high, Airmatic DC briefly releases a portion of the air volume, resulting in a "harder" spring rate to reduce pitch and roll. The air reservoirs are integrated into the spring struts in front and remotely mounted on the subframe in the rear.

The suspension computer considers input from two body level sensors on the front suspension and a third on the rear suspension.  In addition, the Airmatic control unit receives signals from three acceleration sensors on the body and a steering angle sensor, and uses these to determine the required shock absorber force and spring rate.

Solenoid valves on the shock absorbers provide four levels of damping, determined by the computer in response to sensor input.  The valves can switch damping rates in less than 0.05 second. 

The four damping levels include:

Stage 1: soft compression and rebound stage during steady-state driving.
Stage 2: Soft rebound setting and, at the same time, hard compression damping.
Stage 3: Soft compression / hard rebound damping.
Stage 4: Hard rebound and compression for maximum damping stiffness during cornering.

The CLS uses ADS stage 1 when there are small body movements, such as in steady-state driving.  If the speed of movement on the part of the body exceeds a certain level, the system switches back and forth between the second and third damping stages to compensate for body pitch and roll.

Driver-Tuned Suspension

In addition, the driver can select from three suspension damping settings, from maximum comfort to sporty.  With comfort the normal setting, the system switches thresholds between the four ADS stages and the spring rate.  

The driver can select a slightly sportier electronic "map" with the first switch position (one LED lights up), in which harder springing and damping stages are activated earlier than in the Normal position. In addition, the body lowers by 10 mm. 

In the second switch position (two LEDs are lit), softer maps are completely blocked to provide sportier handling.  Ride height is 15 mm lower, and above 40 km/h, damping and springing remain constantly "hard."

Automatic level control maintains the same vehicle height regardless of load.  For traveling over rough roads, the driver can raise the body by 25 mm at the touch of a button.  The car automatically returns to normal ride height if speed briefly exceeds about 120 km/h, or if the vehicle sustains 80-119 km/h for more than five minutes.

Electronic Stability Program (ESP)

Mercedes-Benz was the first auto company to introduce a true electronic stability system on the 1996 S-Class.  All Mercedes-Benz passenger vehicles now come equipped with the Electronic Stability Program (ESP).  The system enhances driver control and helps maintain directional stability in turns as well as when driving straight ahead, including over uneven surfaces and over patchy snow, ice or gravel.  The straight-line traction control function is integrated into ESP.

Mercedes-Benz ESP uses a steering angle sensor, speed sensors at each wheel, sensors for lateral acceleration (or lateral g-force) and vehicle yaw (the vehicle's rotation on a vertical axis), and computer logic specific to the model to calculate the path being steered.  Simultaneously, it measures the car's actual path.

If there's a discernable difference between what the driver asks (through steering) and the vehicle's path, ESP applies selective braking (braking on one wheel, front or rear, left or right) to put the car back on the intended path.  ESP measures a tendency toward understeer (when the front resists steering changes, causing it to "plow") or oversteer (when the rear end "fishtails"). 

When it senses understeer, ESP increases brake pressure to the inside rear wheel.  In an oversteering condition, ESP increases braking to the outside front wheel.  ESP is effective during acceleration, braking and coasting.

Electro-Hydraulic Brake System

Mercedes-Benz, the company that invented ABS anti-lock brakes, traction control and Electronic Stability Program (ESP), also introduced the world's first electro-hydraulic brake system on the 2003 SL roadsters and has now made it standard on the new CLS.  These brakes provide faster, more precise brake response than conventional brake systems, especially in emergencies.

The brake pedal works with a computer that tells four fast-acting valves exactly how hard to apply the brakes on each wheel.  With split-second accuracy, the system can change brake pressure on each wheel over uneven surfaces and can even increase brake pressure on just the outside wheels when braking in turns, taking advantage of the higher loading during cornering. 

ABS anti-lock and ESP work more efficiently since they are more deeply integrated with the brakes, instead of functioning as parallel systems.  A backup hydraulic master cylinder comes into play only if there's a serious problem or electrical failure.

If the driver switches quickly from accelerator to brake pedal, the system recognizes the early signs of an emergency situation and reacts automatically.  With the help of the high-pressure reservoir, the system raises the pressure in the brake connectors and instantaneously moves the pads closer to the brake discs.  This pre-loading can help reduce stopping distance.  In addition, whenever the wipers are on, the system imperceptibly applies the brakes just enough to keep the discs dry, so that brake operation remains fast and consistent in the rain. When ABS intervenes, there are no longer any pulsations through the brake pedal, which not only enhances comfort but safety as well. 

Engine

The new CLS500 is powered by a 5.0-litre V8 that's shared with the CL500, S500, E500 and SL500 models.  Certified as an Ultra-Low-Emissions vehicle, the overhead-cam V8 produces 302 horsepower at 5,600 rpm and 339 lb.-ft. of peak torque at 2,700-4,250 rpm.

Mercedes-Benz V8 engines use single-overhead-cam architecture, with a twin-spark/three-valve-per-cylinder arrangement that ensures high efficiency and performance along with ultra-low emissions.  The V8 engine also uses an electronic throttle with an "adaptive accelerator,"which responds to individual driving styles, tailoring a programmed throttle control curve to each style.  For example, if the engine management system detects a sportier driving style (e.g. repeated sharp acceleration within a short period of time), it adopts a steeper acceleration curve (i.e. the throttle valve opens more quickly).  If the driving style is more leisurely, a less-steep curve is used, resulting in lower fuel consumption.

Its dual ignition system allows an extremely lean fuel-air mixture and late ignition timing during warm-up (retarded by 5-10 crank degrees) that further increases exhaust gas volume and temperature.  In this way, the tri-metal catalytic converter is heated up more quickly and begins converting pollutants even sooner. 

The CLS engine makes use of Motronic ME 2.8 electronic engine management to handle both fuel injection and the phase-shifted dual ignition.  The engine management system is networked via a CAN data bus with other micro-computers for the automatic transmission, traction control and Electronic Stability Program (ESP).  In this way, data is constantly exchanged at lightning speed to ensure good fuel economy and performance and low emissions.

Low-Friction Silicon-Aluminium Cylinder Sleeves

Mercedes-Benz was the first automaker to use innovative cast-in silicon-aluminium cylinder sleeves with a low-friction surface that allows piston-ring spring tension to be reduced by 50 percent.  The efficiency payoff for low internal friction means both fuel savings and increased power.  This sleeve technology is also designed to provide exceptional block stiffness while minimizing weight.  The sleeves are more than 500 grams lighter than conventional iron sleeves, resulting in very light components. 

Dual-Path Intake

Mercedes-Benz V8 engines feature some of the longest intake pipes in the industry, a plus that provides outstanding low- and mid-range power.  Cast into the super-lightweight magnesium intake manifold are long intake passages that spiral around to each cylinder.  Incorporated into the manifold are flaps (one for each cylinder) that are closed below about 3,700 rpm, forcing intake air to take the "long route"through the manifold and build up pressure waves that boost the intake process and improve low- and mid-range torque.

At higher speeds, the flaps open, allowing intake air to take a shortcut -- a more direct route to the cylinders -- for maximum high-speed power and efficiency.  The electronic engine control unit determines precisely when the flaps are opened and closed.

The Building Blocks

Assembling the Mercedes-Benz V8 engine underscores its efficient design.  An exceptionally stiff forged-steel crankshaft is bolted into a pressure-cast aluminium block, and an aluminium oil pan also contributes to block rigidity.  Aluminium pistons are mounted on the connecting rods and then slid into the silicon-aluminium sleeves, which are an integral cast-in part of the block.

Connecting rods must be made in two pieces for assembly on the crank, and Mercedes-Benz engines use hollow, forged steel rods that are made in one piece, then hydraulically "cracked," instead of being machine-cut and reground.  The irregular fracture provides a very strong, durable fit, even at high engine speeds, and shortens the production process since re-grinding isn't necessary.

The two cylinder heads come next, each with a single, hollow camshaft driven by double roller chains and quiet, rubber-coated sprockets.  Twin rocker shafts in each head hold low-friction, roller-tip aluminium rocker arms to actuate the valves.  Housed in the end of each rocker arm is a small hydraulic lifter that ensures quiet, maintenance-free valve operation.  Lightweight magnesium valve covers, the intake manifold and the double-wall sheet-steel exhaust complete the assembly of the basic engine.

Transmission

The World's First Seven-Speed Automatic

The world's first seven-speed automatic transmission helps make the new CLS both faster and more economical.  What's more, the seven-speed provides smooth, barely noticeable gearshifts.  Seven gears provide a wider spread of ratios between first gear and top gear and, at the same time, allow smaller increases in engine speed as the car accelerates through the gears.  This gives the electronic control unit more flexibility in terms of maximizing fuel economy and making the transmission's reaction time extremely fast.

Skips a Gear When You Need To

Unlike most transmissions, the Mercedes-Benz seven-speed transmission will skip up to four gears when the driver downshifts, shifting directly from seventh to fifth, for example, or even sixth to second.  This helps the transmission choose the perfect gear ratio for quick acceleration and ensure smooth, almost imperceptible shifts in the process.

Touch Shift Makes It Easy

Like all Mercedes-Benz vehicles with an automatic transmission, the CLS comes with Touch Shift, which allows the driver to manually select all seven forward speeds by pushing the gear lever slightly left to downshift or right to upshift while in the "Drive" selector position.  It is not necessary to move the lever to another gate to make manual gear changes.  An in-dash gear indicator shows the selected gear.  Though all seven forward speeds of the transmission can be selected, computer control prevents downshifts that would cause the engine to over-rev.  Once the driver has used Touch Shift to manually select a gear, holding the lever to the right returns it to fully automatic Drive mode, and the in-dash gear indicator will then display "D."

Adaptive Shifting Learns What You Like

When not shifting manually, the Mercedes-Benz electronic automatic transmission not only adapts to changes in road grade (delaying upshifts on ascents for climbing power and hastening downshifts on descents for engine braking), but also to an individual's driving style.  The transmission computer adjusts shift points for leisurely driving with smooth upshifts for the best fuel efficiency. 

By comparing road speed changes and load (throttle opening), the transmission computer can discern uphill and downhill grades and adjust shifting as a result.  It avoids annoying shifts back and forth between two gears on a long incline, and delays upshifts on descents (for engine braking), as a driver is likely to do with a manual transmission.  A driver who requires frequent highway merging will find the transmission holds each gear longer for quicker acceleration. 

In addition, a switch next to the shift lever marked "S" and "C" can select either a sport or comfort mode that sets up the transmission to shift appropriately for either spirited driving or calm cruising.

Lock It Up For Better Gas Mileage

While automatic transmission torque converters perform a number of valuable functions (namely dispensing with a clutch and allowing a car to idle in gear), they use up needless fuel once the car is moving.  Like all Mercedes-Benz models, the CLS has a torque converter with a lock-up clutch for maximum fuel efficiency.  The torque converter lock-up clutch can engage in all gears, not just in top gear like many cars.  Slight computer-controlled slippage is allowed to reduce drivetrain vibration.  The lock-up clutch is submerged in transmission oil and uses special long-life friction materials.

CONCLUSION

The new CLS seems destined to become yet another collectible classic from Mercedes-Benz.  When it does, there's little doubt that the CLS will be remembered best for its drop-dead gorgeous looks, even more than for its hot performance and cool high-tech features.  Like most other Mercedes-Benz classics, the CLS will be prized over the long haul for its aesthetic beauty.

Yes, there is a fine line between this four-door coupe and a four-door sedan – a fine roof line, to be exact.  However, one fact is clear – few people will place the CLS in the same category with conventional, conservative four-door sedans.  This car stands out, even in a crowded market.

The CLS buyer will probably be a car enthusiast, someone who loves to drive, who wants to take the long way home.  Because they're driving such a work of art, will CLS buyers have an art collection?  Perhaps, but they're more likely to cherish their car collection.  And, will they have a subscription to a car magazine?  They probably subscribe to all of them.

A deluge of new and very different products from Mercedes-Benz has begun, and the CLS is the perfect car to introduce this new product offensive.