Agile and safe on country roads, ultra-dynamic on the racetrack: The Mercedes-Benz A 45 AMG presented in 2013 exceeded all expectations, and immediately captured the top position in its market. Nonetheless, this worldwide success is no reason for the sports car brand within Mercedes-Benz to rest on its laurels. On the contrary, for after extensive updating the Mercedes-AMG A 45 4MATIC now guarantees even more emotional appeal and driving pleasure. With a peak output of 280 kW (381 hp) and maximum torque of 475 Nm (350 lb-ft), the turbocharged AMG 2.0-litre four-cylinder engine once again comes top in the competitive line-up. The revised transmission ratios, aerodynamic fine-tuning and the new DYNAMIC SELECT driving modes familiar from the Mercedes-AMG GT raise performance to an even higher level. Driving dynamics can be further enhanced with optional extras in the guise of the AMG RIDE CONTROL sports suspension and the AMG DYNAMIC PLUS package.
The entry by Mercedes-AMG into the compact class, and therefore a completely new market segment, in 2013 was a brave move. But it has proved more than worthwhile: within a very short time the compact AMG models have been an impressive success story. The sporty and exciting driving experience plus an emotionally appealing design immediately impressed the dynamic and individualistic target group, and gained new customers for the sports car brand.
And Mercedes-AMG is still going full-throttle: “We never rest on our laurels, but constantly strive to develop our products further,” says Tobias Moers, Chairman of Mercedes-AMG GmbH. “The A 45 still had so much improvement potential that we felt compelled to realise it to the full. Our brand claim simply obliges us to.”
Accordingly the development team at AMG carefully scrutinised every detail of this compact best-seller, whose designation Mercedes-AMG A 45 4MATIC follows the new nomenclature, and applied improvements wherever thorough examination found them to be appropriate for further increases in driving dynamics and enjoyment. The result is certainly impressive, and above all tangible when sitting at the sport steering wheel offering great grip: “We have further refined our turbocharged four-cylinder to develop 280 kW (381 hp) and 475 Nm (350 lb-ft). This means that the Mercedes-AMG A 45 remains the world’s most powerful and dynamic compact sports model,” says Christian Enderle, Head of Engine and Powertrain Development at Mercedes-AMG.
But that is not all. Modifications to the transmission, suspension, electronics, design and appointments have turned the compact sports model into a completely new car: In no other model in this class is true motor racing spirit so obvious as in the Mercedes-AMG A 45.
The power upgrade has lifted this extremely sporty compact into dimensions previously the province of higher vehicle classes: 100 km/h (62 mph) is already reached from a standstill in 4.2 seconds. This means that the new A 45 accelerates 0.4 seconds faster than its predecessor. At the same time, its exemplary fuel consumption has been kept at the level of the previous model: no other high-performance model in this class can match its NEDC fuel consumption from 6.9 litres per 100 kilometres (corresponds to 162 g/km CO2).
The extremely agile, turbocharged four-cylinder engine combines its exhilarating power and exemplary efficiency with another top attribute: the output of 141 kW (191 hp) per litre marks a record for a series production four-cylinder engine, and raises the high-performance AMG power unit to the level of thoroughbred super sports cars.
The engine specialists at AMG mainly achieved this increase in power output with a newly configured valve assembly. In addition the combustion processes have been optimised by reconfigured timing and turbocharging. The maximum charge pressure continues to be 1.8 bar.
AMG 2.0-litre turbocharged engine with numerous high-tech components
The high-tech features of the turbocharged four-cylinder engine from Mercedes‑AMG include spray-guided direct petrol injection. Piezo injectors centrally located in the four combustion chambers inject the fuel at a pressure of up to 200 bar (2900 psi). The combination of multiple fuel injection and multi-spark ignition improves fuel economy and significantly increases thermodynamic efficiency, leading to low exhaust emissions. The twin-scroll turbocharger and maximum dethrottling of the exhaust system improve the charge pressure build-up, and therefore the engine’s response to the accelerator.
Other highlights include: gravity sand-cast all-aluminium crankcase, weight-optimised crank assembly with forged steel crankshaft and forged pistons with friction-optimised piston rings, NANOSLIDE® cylinder wall technology, alternator management and ECO start/stop function. Sophisticated cooling of the engine oil, coolant, charge air and transmission fluid not only improves durability, but also suitability for the racetrack.
The trailblazing technologies and outstanding attributes of this high-end four-cylinder have also elicited the highest praise from independent experts: in 2014 and 2015 the AMG engine received the coveted “International Engine of the Year” award in the 1.8 – 2.0 litres displacement class.
On the road the turbocharged AMG 2.0-litre four-cylinder engine thrills with extremely fast responses to accelerator movements, high torque, enormous flexibility and an emotional engine note. The exhaust system features an automatically controlled exhaust flap as standard. The intensity of the engine note changes according to the currently active AMG DYNAMIC SELECT driving mode. The sound has also been generally refined and perfected.
From the GT and C 63: the new AMG DYNAMIC SELECT driving modes
Already familiar from the Mercedes-AMG GT sports car and the top C-Class model, the Mercedes-AMG C 63, DYNAMIC SELECT now also allows the widest possible selection of driving dynamics in the Mercedes-AMG A 45. To this end the four modes of “Comfort,” “Sport,” “Sport +” and “Individual” are available for selection. The modes are selected using the AMG DYNAMIC SELECT Controller, and modify parameters such as the engine and transmission characteristics. The Controller is positioned in the centre console, behind the selector lever for the AMG SPEEDSHIFT DCT 7-speed sports transmission.
“Comfort” mode allows consumption and comfort-oriented driving with a subdued engine note and gentle gearshifts. The ‘sailing’ function installed for the first time helps to save fuel by decoupling the engine from the powertrain as soon as the driver releases the accelerator within a speed range of 60 to 160 km/h. In Comfort mode the ECO start/stop function is also active, switching the engine off automatically whenever the vehicle stops for a longer period.
“Sport” mode emphasises agility and driving pleasure, with a sporty engine and transmission configuration. The sound of the turbocharged engine becomes more throaty. The ECO start/stop system and the sailing function are inactive.
In “Sport +” mode the power transmission reacts even more immediately. The shift strategy of the transmission is optimally modified for the needs of a very sporty driving style – including extremely short shift times, emotional double-declutching and faster responses to the accelerator. Partial cylinder suppression by means of a momentary and precisely defined retardation of ignition and injection under full throttle speeds up the gear changes, and is also audible to the driver.
Over and above the preconfigured modes, the “Individual” driving mode makes it possible to vary individual parameters for the engine, manual or automatic transmission mode and 3-stage ESP®.
All DYNAMIC SELECT modes are also visualised in the cockpit display. The driver sees a special icon and corresponding information in the central display of the AMG instrument cluster. A pop-up window also appears on the free-standing central display whenever the transmission mode is changed: depending on the mode, the animated Mercedes-AMG A 45 is shown with an appropriate graphic and colour presentation. While subdued shades of blue predominate in “Comfort,” the car is shown on a racetrack in “Race” mode (included with the optional DYNAMIC PLUS package or the AMG RIDE CONTROL sport suspension – including red/white kerbs.