Mercedes-Benz CL550 4MATIC - V8 biturbo engine

With a design perfected through the greatest sense of style, exclusive appointments and cutting-edge technology, the extensively updated 2011 Mercedes-Benz CL-Class reinforces its claim to supremacy as the ultimate in automotive refinement. The entirely redesigned 429 hp. V8 biturbo engine of the CL550 4MATIC and the 536 hp. AMG V8 biturbo of the CL63 AMG open a new dimension of performance in the luxury coupé category. Performance and fuel economy improve thanks to the newly-developed BlueDIRECT technology with third-generation spray-guided direct injection as well as energy-efficient control of alternator, fuel pump, air-conditioning compressor and power-assisted steering system. In addition, the Mercedes- Benz engineers equipped the CL with state-of-the-art multimedia technology and hand-finished components to help retain its position as the epitome of quality in its class. These two new V8 models, as well as the V12-powered CL600 and CL65 AMG go on-sale in the U.S. in November 2010.

Mercedes-Benz CL550 4MATIC

With the new generation of the CL, the Stuttgart-based automaker focuses on fuel consumption and exhaust gas emissions in the exclusive high-end segment. According to Dr. Dieter Zetsche, Chairman of the Board of Management of Daimler AG: "The CL is the ideal ambassador for our brand. To a special degree it integrates the things that go to make a Mercedes-Benz: fascination, perfection and responsibility. And with the new generation we raise the ante especially in the area of efficiency. But in the realms of design, safety, comfort and performance, too, the CL shows: ahead is where Mercedes is."

A combination of cutting-edge camera and radar-based assistance systems such as the innovative Active Lane Keeping Assist and the Active Blind Spot Assist make the CL a "thinking" partner of the driver. The modified Active Body Control (ABC) with crosswind stabilization system and the Direct-Steer system also contribute to enhancing safety and driving enjoyment.

The exterior appearance of the new CL generation is characterized by the dramatic profile of the hood, the dynamic V-shape radiator grille and sweeping headlamps - design details that discreetly but effectively emphasize the car's elegant yet powerful lines.

The front bumper presents a new design with three air intake openings and a chrome trim strip. An LED strip with chrome trim for the daytime running lamps is elegantly integrated into the lower fascia. With standard Bi-Xenon headlights and Adaptive Highbeam Assist, the headlamps offer state-of-the-art illumination technology. The latest LED technology in the turn indicators and position marker lamps round-off the car's advanced look. The rear of the vehicle is characterized by the newly-designed tail lights.

Mercedes-Benz CL550 4MATIC

With its 4,663 cubic centimeters of displacement the new V8 biturbo engine in the 2011 CL550 4MATIC features BlueDIRECT technology and delivers impressive power. The eight-cylinder engine produces 429 hp so that despite 0.8 liters less displacement, it is still around 12 percent more powerful than its predecessor. At the same time, torque was raised to 516 lb-ft - an increase of 32 percent. The CL550 4MATIC requires a mere 4.8 seconds to accelerate from a standstill to 60 mph. In summary, the 2011 CL550 4MATIC is significantly more agile, torquey and fuel efficient than its predecessor.

The new engine in the CL550 4MATIC is mated to a seven-speed automatic transmission which has undergone significant revision, while V12 models retain the proven five-speed automatic transmission due to their extremely high torque at low engine speeds. The DIRECT-SELECT lever on the steering column enables the driver to select "P", "N", "R" and "D" by nudging the selector. The operating commands are transferred electronically by wire.

Mercedes-Benz CL550 4MATIC

The seven-speed automatic transmission was improved in detail by the Mercedes engineers. The aim was to further reduce converter slip in the connection with the engine and thus optimize efficiency. In addition, the much increased torque of the V8 biturbo engine in the CL550 4MATIC raised new demands on the absorption of cyclic irregularities and vibrations in the transmission. The Mercedes-Benz developers met this challenge in the new transmission with a new torsional vibration damper. It is designed as a double turbo-damper and additionally fitted with a centrifugal pendulum which shifts the mass center of gravity as a function of engine speed and enables comfortable vehicle operation even at lower engine speeds. Moreover, the optimal damping already makes a distinct reduction in the slip of the torque converter lockup clutch at low loads. The result: in ECO mode the engine speed could be reduced, contributing greatly to cut fuel consumption. Plus, it ensures an even quicker response to accelerator commands.

A new hydraulic circuit and optimized torque converter characteristics also help to improve efficiency and performance. A further consumption-cutting measure is a new lower-viscosity automatic transmission fluid (ATF), which has a longer life yet the same cooling performance. As a result, the CL550 4MATIC only needs a transmission fluid change every 78,000 miles.

Mercedes-Benz CL550 4MATIC

The engine management ensures that the engine is only switched off if certain preconditions are met. The starter battery must have sufficient charge, for example, and the engine must be at the necessary operating temperature for efficient emissions control. The same applies to the interior temperature selected by the driver: if this has not yet been reached, the engine is not switched off when the car comes to a stop. The onboard network management system makes sure that active audio, telephone or video functions are not interrupted by the stop/start function.

A green "ECO" symbol in the AMG main menu shows the driver that the Controlled Efficiency stop/start function is active. Should one of the above criteria prevent activation of the system, this is shown in the central display by the message "Stop/start inactive" and a yellow "ECO" symbol. In the two more performance-oriented driving modes "S" (Sport) and "M" (Manual), the stop/start function is always deactivated. If required, the driver can also switch it off while in "C" mode.

The engine and transmission are even more agile in the "S" (Sport) mode. Accelerator pedal movements trigger a more direct traction response, making the downshifts more spontaneous. The engine speed is allowed to reach a higher level in each gear, while the gearshifts are around 25 percent faster than in "C". In the manual shift mode "M", gearshifts at full throttle take just 100 milliseconds, a reduction of 50 percent compared to "C". In "S" and "M" modes, the engine management system partially suppresses the cylinders: interrupting ignition and injection under full load leads to even faster gearshifts than before.

Mercedes-Benz CL550 4MATIC

Ultra-fast, spontaneous multiple downshifts are another strength of the AMG SPEEDSHIFT MCT 7-speed sports transmission. For instance, kickdown allows gearshifts straight from seventh down to fourth gear, or from fifth to second. In the "S" and "M" driving modes the automatic rev-matching function is active. Every manual or automatic downshift is accompanied by precisely metered engine revs - incrementally from "S" to "M". This not only adds to the driver's emotional experience, but the load-free downshift minimizes load-change reactions, which is particularly helpful when braking into bends - and also enhances safety in slippery conditions.

In manual "M" mode the driver also benefits from the high torque of the V8 biturbo engine, as there is no automatic downshift under full load and kickdown. The transmission remains steadfastly in the selected gear and does not perform an automatic upshift in manual mode even when the rev limit is reached. In "M" mode the AMG instrument cluster displays the current gear and alerts the driver to upshift by means of a red "up" symbol just before the needle reaches the red zone. When approaching the lower rev limit, e.g. when braking, there is an automatic downshift to the next lower gear.

Mercedes-Benz CL550 4MATIC

With state-of-the-art assistance and protection systems the 2011 CL-Class affirms its status as an automotive masterwork and technology platform. The attentive assistants turn the car into an "intelligent" partner which is able to "see", "feel", respond "instinctively" to danger and act "on its own initiative" in order to avoid accidents or reduce their severity. The trailblazing driver assistance systems in the 2011 CL-Class are based on cutting-edge radar, camera and sensor technology. Celebrating its premiere on the 2011 CL-Class, the optional Active Lane Keeping Assist (standard on V12 models) monitors lane markings and if the vehicle threatens to cross a dashed line the system actuates an electric motor in the steering wheel, causing it to vibrate briefly - giving the driver a discreet but effective warning to countersteer immediately. If the coupe unintentionally crosses a solid line, the system intervenes by gently braking the wheels of the opposite side of the car, helping the driver to stay in the lane. Active Lane Keeping Assist works through the existing Electronic Stability Program ESP®.

Active Lane-Keeping Assist evaluates information provided by a camera mounted on the inside of the windshield which identifies the contrast between the road surface and the lane markings. In addition, the radar system scans the side of the roadway for crash barriers and other roadway edge markings. This Mercedes assistance system also evaluates the driver's actions and can reliably determine whether the car is departing from the lane intentionally or not. Consequently, there is no warning if the driver accelerates hard just before overtaking, when merging onto a highway, braking hard or steering into a curve.

Another component of the optional Driver Assistance Package (standard on V12 models) is Active Blind Spot Assist, a system that uses a multi-stage warning concept. If it detects that a change of lane would be too dangerous, it warns the driver by displaying a red triangle in the glass of the exterior mirror. Close-range radar sensors monitor the area immediately to the side and to the rear of the car. If the driver disregards this warning and, for example, actuates the turn indicator, an audible warning also sounds. If the driver continues to ignore the warnings and comes dangerously close to a vehicle in the neighboring lane, corrective braking intervention via ESP® is applied to the wheels of the opposite side of the vehicle. This causes a yaw movement about the car's vertical axis due to the unequal distribution of braking forces. If, despite this course correction, an accident cannot be avoided the Active Blind Spot Assist system reduces the consequences of a collision.

Mercedes-Benz CL550 4MATIC

Adaptive Highbeam Assist is another standard system on the 2011 CL-Class. This camera-based system can recognize oncoming vehicles or vehicles ahead with their lights on, and then controls the headlamps to ensure the best possible beam range without dazzling other drivers. In addition, Mercedes-Benz offers the Night View Assist Plus system, featuring a special infrared camera for pedestrian detection: as soon as the system detects pedestrians on the road ahead, they are highlighted additionally in the display in order to better catch the driver's attention.

Mercedes-Benz offers another radar-based system as a component of the optional Driver Assistance Package (standard on V12 models) - PRE-SAFE® Brake. If the driver is distracted and fails to recognize the imminent danger of a rear-end collision, this system can intervene and brake the vehicle independently. If the driver fails to react even after automatic, partial braking action, this latest version of the PRE-SAFE® Brake activates maximum braking pressure around 0.6 seconds before what is now an unavoidable collision. This emergency braking action can significantly mitigate the severity of the impact. The PRE-SAFE® Brake thus acts as a kind of "electronic crumple zone".

Drowsiness is one of the most common causes of accidents. According to the National Sleep Foundation, fifty-four percent of motorists have driven while drowsy at least once in the past year, and 28 percent do so at least once per month. This is why Mercedes experts have developed the ATTENTION ASSIST system which forms part of the standard equipment of the 2011 CL-Class. The system continuously evaluates more than 70 different parameters in order to identify driver drowsiness and provide a warning before the dangerous microsleep phase begins. Observing the driver's steering behavior has proved to be an especially strong indicator: several years of practical research by Mercedes-Benz has shown that drowsy drivers make minor steering errors which they often correct very rapidly in a characteristic way. This steering behavior is recognized by a special steering angle sensor. Observing the driver's eyes cannot always provide conclusive evidence of sleep since many drivers can experience microsleep with their eyes open.

The 2011 CL also meets the highest standards in terms of driving dynamics and agility thanks to Direct-Steer, with a steering ratio that varies with the steering angle, and modified Active Body Control (ABC) with crosswind stabilization (standard for the CL600 and AMG models). This latest stage in active suspension development modifies the wheel load distribution via the ABC spring struts within milliseconds, depending on crosswind direction and intensity, to the extent that it can largely compensate the effects of the crosswind.

Mercedes-Benz developers and designers perfected the CL interior paying careful attention to detail. A total of four different kinds of trim open up the possibilities for perfectly matched material and color concepts according to personal taste: apart from dark high-gloss burl walnut, there is also black ash wood. Twelve cylinder models additionally offer high-gloss poplar and both AMG models have Carbon Fiber trim available. Important to note - consistent with the corporate philosophy of sustainability at Mercedes-Benz, the CL uses only European wood from renewable forestry sources. Most of the wood parts are hand-made and matched individually for color and grain by experienced craftsmen.

The standard COMAND control and display system with Bluetooth®, USB and SD card interfaces offers customers the possibility of integrating their stored data with the vehicle. A standard Media Interface for mobile audio and video devices such as an iPod® is integrated into the glove compartment. The standard navigation system features nationwide navigation and a detailed three-dimension map display with data stored on a 40-gigabyte hard disc, facilitating extremely rapid route calculation. For musical entertainment COMAND provides SIRIUS and HD radio, a 6-disc CD/DVD player with MP3 capability, an equalizer with speed-dependent volume control and the MUSIC REGISTER with a 7.2 gigabyte hard disc which stores around 2500 digital music files in MP3, AAC or WMA format (which can be conveniently transferred to the REGISTER from PC memory cards). The system recognizes music files played on CD, DVD or from the MUSIC REGISTER using its stored Gracenote® database, and shows the title, album and performer in the color display.

Standard equipment also includes the latest-generation of Voice Control which operates the navigation, telephone and audio devices via whole-word input. The driver no longer needs to spell out his commands but simply speaks whole words when entering a destination or choosing a radio station or a music title from the MUSIC REGISTER, or when calling up a name from the phone book.

Mercedes-Benz stylishly underlines the exceptional status of the twelve-cylinder CL600 with numerous distinguishing features in the exterior and interior. In addition to the model-specific radiator grille with two twin louvers, these include the V12 emblem on the front fenders, model-specific 19-inch multispoke wheels and a large range of standard equipment.

The flagship model remains the CL600 with its 510 hp twelve-cylinder biturbo engine, which accelerates the luxury coupe from a standstill to 60 mph in impressive 4.5 seconds. Maximum torque is 612 lb-ft at 1,800 rpm, which makes the 5.5-litre engine one of the world's most powerful series-production car engines. The V12 combines its impressive performance potential with exemplary smoothness and quiet running, ideal for refined and enjoyable travel.

The crankcase of the twelve-cylinder engine is made from diecast aluminum, while diecast magnesium is used for the cylinder-head covers. The engine uses lightweight components such as fracture-split ("cracked") connecting rods made from high-strength forged-steel alloy, pistons made from a high-quality aluminum alloy, hollow camshafts of induction-hardened forged steel, a weight-optimized forged-steel crankshaft and a diecast aluminum sump.

The turbines of the two turbochargers are integrated into the exhaust manifolds on both sides to save space, and are in the best position for high efficiency. The compressed air flows through two close-coupled water intercoolers on the cylinder head covers. Depending on the engine load the air is cooled by up to 212 degrees Fahrenheit, achieving just the right temperature and density for the combustion process.