The philosophy behind this four-door mid-series coupé matches that of the successful CLS 63 AMG, the trendsetter among four-door high-performance coupés. A glance at this high-tech package suffices to show that the CLS 45 AMG also has all the typical DNA to make it a perfect representative of the AMG’s Driving Performance brand claim: with a peak output of 265 kW (360 hp) and maximum torque of 450 Nm (332 lb-ft), its turbocharged engine is not only the most powerful four-cylinder unit in series production anywhere in the world but also a highly efficient one that meets the EU6 emissions standard. With fuel consumption of 6.9 l/100 km (34.08 mpg/US, 14.49 km/l) according to NEDC combined figures, the CLA 45 AMG meets even the most exacting requirements. The performance-oriented AMG 4MATIC all-wheel drive of the CLA 45 AMG similarly sets a new benchmark in its competitive segment.
Ola Källenius, Chairman of Mercedes-AMG GmbH: “With the CLA 45 AMG, Mercedes-AMG is launching a unique and highly desirable automobile with all the typical DNA of AMG. A high-tech package that includes the most powerful series-production four-cylinder engine in the world as well as performance-oriented AMG 4MATIC all-wheel drive, it embodies Driving Performance at its best.”
The new four-door high-performance coupé offers an exceptional combination of an excitingly sporty driving experience, extravagant design and exclusive individuality. With the CLA 45 AMG Mercedes-AMG is establishing a completely new segment – as it did previously with the CLS 63 AMG Shooting Brake (2012) and the CLS 55 AMG (2004). At the time of their launch, neither of these AMG models had any direct rivals, but went on to inspire other automotive manufacturers. Turbocharged engine, all-wheel drive and the AMG SPEEDSHIFT DCT 7-speed sports transmission – the CLA 45 AMG features the same drive system that is already powering the A 45 AMG to deliver highly dynamic and efficient performance.
Typically AMG: the most powerful series-production four-cylinder turbo engine in the world
A glance at the technical data for the CLA 45 AMG shows: the AMG 2.0-litre turbo engine, with a maximum output of 265 kW (360 hp) and up to 450 Nm (332 lb-ft) of torque, is the most powerful turbocharged four-cylinder engine in series production anywhere in the world.
The combination of high performance and torque, together with the performance-oriented AMG 4MATIC all-wheel-drive system, gives the CLA 45 AMG driving characteristics almost on a par with those of a sports car. The performance coupé accelerates from zero to 100 km/h in 4.6 seconds and its top speed is 250 km/h/155 mph (electronically limited). But the AMG 2.0-litre turbo engine is impressive not only in terms of its dynamic performance but also with regard to its efficiency and environmental compatibility. The CLA 45 AMG achieves a fuel consumption level of 6.9 l/100 km (34.08 mpg/US, 14.49 km/l) according to NEDC combined figures, while it already meets the EU6 emissions standard that only comes into effect in 2015 as well as the limit for the particle count per kilometre of 6 × 1011 part./km that will become mandatory in 2017.
The basis for these impressive figures is provided by the high-tech package which has been put together by Mercedes-AMG. As a high-performance engine belonging to the BlueDIRECT family, the four-cylinder turbo engine features spray-guided direct petrol injection via piezo injectors positioned centrally in the four combustion chambers. The combination of multiple fuel injection and multiple spark ignition improves fuel utilisation and increases thermodynamic efficiency substantially, leading to lower exhaust emissions. Other highlights include the gravity-die sandcast all-aluminium crankcase, weight-optimised crank assembly with forged steel crankshaft and forged pistons with friction-optimised piston rings, NANOSLIDE® cylinder wall technology, air-water charge air cooling, generator management and ECO start/stop function.
Twin-scroll turbochargers and AMG sports exhaust system with exhaust flap
Mercedes-AMG addresses the essential challenges concerning the response of small-displacement turbo engines by means of a twin-scroll turbocharger, maximum derestriction of the exhaust system and an innovative injection strategy. The twin-scroll technology provides for a more spontaneous build-up of charge pressure, making effective use of exhaust gas back pressure, exhaust gas temperature and exhaust gas impulse. This results in a swifter build-up of torque right from the lower rev range. As a positive side-effect, the twin-scroll technology also benefits fuel consumption and exhaust emissions. With a maximum charge pressure of 1.8 bar (26 psi), the AMG 2.0-litre four-cylinder turbo engine leads the field in this respect, too.
The AMG sports exhaust system features large pipe cross-sections and an automatically controlled exhaust flap. This technology, which is familiar from the SLK 55 AMG, reconciles the two apparently conflicting aims of tangible dynamism and hallmark Mercedes comfort on long journeys. The flap is continuously adjusted by map control according to the power called up by the driver, load status and engine speed. The AMG sports exhaust system emits a fascinating, full engine sound that is particularly impressive during powerful acceleration.
An AMG Performance exhaust system with exhaust flap is available as an option for the A 45 AMG. This provides for an even more emotional and striking engine sound when the throttle is open and during gear shifting. The double-declutching function during downshifting and the interruption of ignition and injection during upshifting under full load produce a particularly throaty sound with the AMG Performance exhaust system and create a level of emotionality which is otherwise the preserve of engines with more than four cylinders.
High-performance cooling system with components from the SLS AMG
The high driving dynamics of the CLA 45 AMG call for a highly effective cooling system. On the basis of the components from the SLS AMG, a low-temperature circuit is additionally deployed for air-water charge air cooling of the four-cylinder turbo engine. The cooler extending across the complete front level of the cooling module is supplemented by an additional cooler in the wheel arch. Together with the charge air cooler, which is connected in series, a high-performance electric pump ensures the required flow through the water coolers located behind the large intake ports. This provides for ideal cooling of the highly compressed charge air, thereby contributing towards optimum engine performance.
The cooling of the transmission oil is integrated into the water cooling circuit for the engine. The water cooler positioned behind the front apron 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.
“One man, one engine”: a tradition of hand-built excellence
As is the case with all eight- and twelve-cylinder engines, the new AMG four‑cylinder turbo engine is 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 – where all BlueDIRECT four-cylinder engines are built for the A- and B-Class models. 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 DNA of Mercedes-Benz’s high-performance brand.
Dual clutch transmission and all-wheel drive – the drive package on board the new CLA 45 AMG is a demonstration of high-end engineering prowess. The AMG SPEEDSHIFT DCT 7-speed sports transmission is directly flange-mounted on the transversely installed engine. Key software modules have been adopted from the SLS AMG super sports car with its inspirational power transmission concept. The dual clutch transmission of the CLA 45 AMG features seven gears, three driving programmes, a double-declutching function and RACE START for optimum acceleration. The strengths of the AMG DCT sports transmission include spontaneous gear shifting without any interruption in tractive power, a tailor-made control strategy, extremely smooth and easy gear shifting and a high level of efficiency. Reinforced gear wheels provide for maximum stability. Synchroniser rings with carbon-fibre friction linings improve durability while also optimising the response time during manual gear-changing – the ideal basis for ambitious laps on cordoned-off race tracks.
“Momentary M mode” for even greater dynamism and driving enjoyment
Another special feature designed to enhance dynamic performance and driving enjoyment is the so-called “Momentary M mode.” 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 dynamism and performance of gear-shifting in manual mode in all the automatic driving programmes, with automatic up-shifting on meeting the rpm limit into the bargain. 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 similarly sporty in character to those of the SLS AMG GT super sports car. Briefly and precisely interrupting ignition and injection under full load leads to even faster gearshifts in “M” and “S,” with a more emotional sound than ever. In “C” mode (Controlled Efficiency), tangibly soft transmission and engine characteristics support a fuel-efficient and comfort-oriented driving style. In addition, in “C” mode the ECO start/stop function is active.