Mercedes-Benz CLA45 AMG
Mercedes-Benz AMG celebrated its world debut of the 2014 model year CLA45 AMG at the 2013 New York International Auto Show. The four-door coupe follows in the design footsteps of the successful CLS63 AMG, the trendsetter for four-door high-performance coupes. With a maximum power output of 355 hp and a peak torque of 332 lb.-ft., the 2014 CLA45 AMG is the world's most powerful four-cylinder engine built in series production. The performance-oriented AMG 4MATIC all-wheel drive on the CLA45 AMG sets new standards in the competitive segment as well. The 2014 CLA45 AMG goes on sale in the U.S. this November. Ola Källenius, CEO of Mercedes-AMG GmbH: "In the CLA45 AMG, Mercedes-AMG presents a unique and absolutely desirable automobile with the characteristic AMG genes. The high-tech package with the world's most powerful four-cylinder production engine and performance-oriented AMG 4MATIC all-wheel drive stands for 'Driving Performance' at its best." Mercedes-Benz AMG establishes a new segment with the exciting new four-door performance coupe CLA45 AMG.
The 2014 CLA45 AMG 2.0-liter turbo engine is the most powerful turbocharged four-cylinder production engine with a maximum power output of 355 hp and a peak torque of 332 lb.-ft. of torque.
The combination of high power, strong torque and performance-oriented AMG 4MATIC all-wheel drive lend the CLA45 AMG superb driving performance. The powerful coupe sprints from 0-60 in 4.5 seconds. Top speed is electronically limited to 155 mph. Mercedes-AMG achieves these impressive figures by the use of high-tech engineering throughout the engine and related systems. The combination of multiple injection and multiple spark ignition improves fuel utilization and substantially increases thermodynamic efficiency, leading to low exhaust emissions. Other highlights include the sand-cast allaluminum crankcase, weight-optimized crank assembly with forged steel crankshaft and forged pistons with friction-optimized piston rings, NANOSLIDE cylinder lining technology, water-to-air intercooling, alternator management and ECO Start/Stop function.
Mercedes-AMG masters the essential challenges concerning the response of small-displacement turbo engines by means of a twin-scroll turbocharger, minimized restrictions in the exhaust system and an innovative injection strategy. The twin-scroll technology makes effective use of exhaust gas back pressure, temperature and momentum to provide a more spontaneous build-up of boost pressure. This results in a quicker build-up of torque from low revs. As a positive side effect, the twin-scroll technology also benefits fuel consumption and exhaust emissions. With a maximum boost pressure of 26.1 psi (1.8 bar), the AMG 2.0-liter four-cylinder turbo engine also leads the field in this respect.
The AMG performance exhaust system features large pipe cross-sections and an automatically controlled butterfly valve in the exhaust system. This technology, which is familiar from the SLK55 AMG, allows the CLA45 to deliver a commanding roar on acceleration while also offering a refined note during sustained speed, such as on the highway. The valve is continuously adjusted by the engine mapping in line with the accelerator input, load status and engine speed.
It provides for an even more emotional and striking exhaust note when the throttle is open and when shifting gears. The rev-matching function during downshifts and the suppression of ignition and injection during upshifts under full load produce a particularly powerful sound with the AMG Performance exhaust system creates a level of emotion that is typically reserved for engines with more than four cylinders.
The high level of driving dynamics of the 2014 CLA45 AMG call for a highly effective cooling system. Similar to the technology of the SLS AMG GT, a lowtemperature circuit is additionally installed for water-to-air intercooling of the charge air of the four-cylinder turbo engine. The large radiator at the very front of the cooling module is supplemented by an additional radiator in the wheel well. A high-performance electric pump provides the required flow through the water radiators located behind the large intake ports and the intercooler connected in line. This provides ideal cooling of the highly compressed charge air, thereby contributing towards optimum engine performance.
Cooling of the transmission oil is integrated into the hot-water cooling circuit of the engine. The radiator positioned behind the front fascia is supported by the heat exchanger, which is fitted directly on the transmission and supplied with cooling water as required by means of an auxiliary pump.
Like all eight- and twelve-cylinder engines, the new AMG 2.0-liter four-cylinder turbo engine is also hand-built according to the traditional AMG philosophy of "one man, one engine." An exclusive assembly line has been set up for the new AMG engine at the Mercedes-Benz engine production plant in Kölleda, Germany. A characteristic feature of the "one man, one engine" production process is the AMG engine plate bearing the signature of the responsible engine fitter. Apart from serving as an AMG hallmark confirming superlative production quality, the AMG engine plate also attests to the peerless genes of the Mercedes-Benz high-performance brand.
Dual clutch transmission and all-wheel drive – the drive train on board the CLA45 AMG is a demonstration of high-end engineering prowess. The AMG SPEEDSHIFT DCT 7-Speed sports transmission is mounted directly to the transversely installed AMG 2.0-liter four-cylinder turbo engine. The dual clutch transmission of the CLA45 AMG features seven gears, three driving programs, a rev-matching function and RACE START for optimum acceleration. The highlights of the AMG DCT sports transmission include spontaneous gearshifts without interruption in tractive power, a tailor-made control strategy, extremely smooth and easy gearshifts and a high level of efficiency. Reinforced gears ensure maximum durability. Synchronizer rings with carbon-fiber friction linings improve longevity while also optimizing response during manual gearshifts – the ideal situation for ambitious lap times on a closed circuit.
Another special feature designed to enhance dynamic performance and driving pleasure is the so-called "Momentary M" program. In C and S mode, this enables the driver to activate manual mode ("M") without having to remove a hand from the steering wheel by pressing the "up" or "down" shift paddle once. In "Momentary M" mode, the driver experiences the dynamics and performance in all automatic driving programs, with automatic upshifts upon reaching the rev limit. This allows the driver to devote his full attention to the vehicle's impressive performance.
The shift times in manual mode "M" and in sport mode "S" are of similar sporty character as those of the SLS AMG GT super sports car. Brief and precise suppression of ignition and injection under full load leads to even faster gearshifts with a more emotional sound than ever. In "C" mode (Controlled Efficiency), soft transmission and engine characteristics are conducive to a fuel-efficient and comfort-oriented driving style. In addition, the ECO Start/Stop function is active in "C" mode.
The 2014 CLA45 AMG features variable AMG 4MATIC all-wheel drive as standard. In developing this all-wheel-drive system, the focus was on "performance" and "dynamic spirit." The power transfer to the rear drive train is facilitated by a compact power take-off unit (PTU), which is fully integrated into the 7-speed sports transmission. Its lubrication is supplied by the oil circuit of the sports transmission. This configuration results in substantial weight advantages compared with rival systems, which branch off power by means of an add-on component with dedicated circuit. Together with the friction-minimized tapered roller bearings, the PTU delivers excellent efficiency. As an additional bonus, the system weight of the new AMG 4MATIC all-wheel drive is up to 25 percent less than the all-wheel-drive versions offered by the competition.
A two-part propeller shaft transfers the power of the AMG 2.0-liter fourcylinder turbo engine to the rear axle. In the interests of favorable weight distribution, an electrohydraulically controlled multi-disc clutch is integrated into the rear axle differential. The multi-disc clutch immediately detects slip at the front axle. A hydraulic pump instantaneously presses the discs together and channels the engine torque to the rear wheels as necessary. All this takes place virtually unnoticed by the driver. To enable particularly fast response, the pump is always active and does not require to be started up each time it is needed, as is usually the case with other systems. Torque split is fully variable: in normal driving, the CLA45 AMG has front-wheel drive bias in the interests of optimum efficiency. If the driving dynamics require, the variable AMG 4MATIC all-wheel drive splits the torque between front and rear axle at a ratio of up to 50 : 50 percent. The variables influencing the torque split ratio are vehicle speed, lateral and longitudinal acceleration, steering angle, speed difference between the individual wheels, selected gear and accelerator position.
An exclusive feature is the interaction of the AMG 4MATIC all-wheel drive with the 3-stage ESP® and ESP® Curve Dynamic Assist. The three ESP® stages enable the driver to vary the dynamics of the CLA45 AMG according to his/her individual preferences at the push of a button. The safety-oriented "ESP ON" mode supports the driver in maintaining neutral handling characteristics. The system initiates braking intervention on one or more wheels and reduces the engine torque on detecting the onset of unstable driving conditions.
Briefly pressing the ESP® button activates "SPORT Handling" mode. This dynamically oriented driving mode applies appropriate control strategies for delayed ESP® intervention and increased torque at the rear axle. This means more driving pleasure for drivers who are keen to exploit the vehicle's dynamic potential. Pressing and holding the ESP® button activates "ESP OFF" mode. In this mode, the ESP® functions are not available. ESP OFF should only be used by experienced drivers on closed circuits. However, when the driver steps on the brake pedal in "SPORT Handling" or "ESP OFF" mode, all safety functions of the ESP® system are available for the duration of the brake application.
ESP® Curve Dynamic Assist complements the ESP® system to perfection: during dynamic cornering, imperceptible brake intervention on an inside wheel vectors torque to create a defined yaw movement around the vertical axis, resulting in precise and safe turn-in of the CLA45 AMG. ESP® Curve Dynamic Assist is adapted according to the selected ESP® mode. In "SPORT Handling" and "ESP OFF" mode it aids in fulfilling the driver's wish for increased agility and driving dynamics. ESP® Curve Dynamic Assist is an additional function of the Electronic Stability Program which noticeably improves not only agility, but also active driving safety at the limits of the laws of physics.
Like every AMG high-performance automobile, the CLA45 AMG also incorporates sophisticated axle technology. For enhanced driving dynamics, the three-link front suspension is provided with stiffer steering knuckles and totally new elastokinematics. Newly developed, more rigid bearings are employed in the lower link plane. These ensure more agile turn-in properties and more precise and direct feedback from the road surface. The more rigid bearings also lead to higher camber stability, allowing higher cornering speeds. In developing the complete front axle, great importance has been attached to attaining the best possible traction under highly dynamic driving conditions.
The four-link rear axle of the CLA45 AMG is also a totally new development. In the course of optimizing the elastokinematics, the strut bearings were modified for maximum driving dynamics and control. The rear axle carrier is fitted with more rigid bearings for increased directional stability; the subframe is rigidly bolted to the body. The AMG sports suspension with its specifically tuned spring/damper units and larger stabilizers ensures high lateral acceleration and a reduced body rolling tendency in fast S-bends. The CLA45 AMG comes standard with twin-spoke AMG light-alloy wheels inlayed in titanium gray with a high-sheen finish, fitted with size 235/40 R 18 tires.
The electromechanical dual pinion AMG speed-sensitive sports steering with AMG-specific, speed-dependent power assist and a constant steering ratio (14.5 : 1) enables high steering precision and agility. The electric motor is installed in space-saving configuration on the steering gear. The AMG high-performance braking system with ventilated and perforated front and rear brake discs measuring 13.8” x 1.2” at the front and 13.0” x 0.8” at the rear provides spontaneous and reliable deceleration.
The new CLA45 AMG leaves no doubt even at first glance; similarities with the CLS63 AMG are intentional. Mercedes-AMG complements the expressive design idiom with distinctive AMG elements and thus creates a new design icon. The CLA was born with sporty proportions – the AMG "twin blade" radiator grille and the cross member in the AMG front fascia, both painted matte titanium gray, reinforce the dynamic appearance further. The large air inlet ports on the sides are framed by black winglets and improve the air flow to the cooling modules located behind them. Bi-xenon headlights are part of the standard equipment.
Side sill panels with matte titanium gray inserts catch the eye in the side view. Typical elements of a powerful top-of-the-line AMG model furthermore are the twin-spoke AMG light-alloy wheels, inlayed in titanium gray and with a highsheen finish, as well as the "TURBO AMG" lettering on the fender. The expressive feature in the rear is the AMG rear fascia of the CLA45 AMG. It includes stylized side air vents as well as a large diffuser insert and matte titanium gray trim elements. The two chrome-plated tailpipes of the AMG exhaust system with butterfly valve emphasize the dynamic spirit. The striking LED tail lights come as standard equipment.
Impressive quality, high-end materials as well as the dynamic spirit and exclusive character typical of Mercedes-AMG – the interior of the CLA45 AMG leaves nothing to be desired. Sport seats wrapped in ARTICO man-made leather and DINAMICA microfibers with red contrasting topstitching, red seat belts, the multifunction steering wheel with shift paddles, the AMG DRIVE UNIT and front AMG door sill panels all come as standard. The brushed aluminum trim of the instrument panel is perfectly matched to the five anodized ventilation nozzles. The AMG instrument cluster provides information with a central color display, the AMG main menu and the RACETIMER.
Source: Mercedes-Benz Press