Looking to better the Honda Type R and Renault Megane R.S.
Mercedes-Benz wants to have the ‘ultimate hot hatch’ crown in order to keep its status of providing the ultimate driving dynamics and expressive design with their latest Mercedes-AMG compact A45 4MATIC+ and A45 S 4MATIC+ sports cars. While setting numerous new standards, the engineers at AMG, where these cars were initiated, have taken all the best know how from the motorsports engagements around the globe and shoehorned them into this compact hot hatch.
New turbocharged four-cylinder
With an output of up to 310 kW (421 hp), the completely newly developed 2.0-litre engine is the world’s most powerful turbocharged four-cylinder manufactured for series production. Mercedes-AMG has bettered the output of the preceding engine by 30 kW(40 hp).
Maximum torque has also increased from 475 to up to 500 newton metres. With an output per litre of up to 155 kW (211 hp), the new Mercedes-AMG high-performance turbo engine even ranks ahead of many well-known super-sports car engines. The new, highly efficient powerpack is produced on an innovative production line in Affalterbach, on the “One Man, One Engine” principle.
In the 45 models
The four-cylinder ensures extremely agile performance in two output classes: with 310 kW (421 hp) as the S-model and with 285 kW (387 hp) in the basic version.
This positioning logic has already proved successful for the AMG Performance models with a V8 engine, and meets individual customer wishes even better. The new compact sportscars absolve the sprint from zero to 100 km/h in record time: the A45 S 4MATIC+ requires only 3.9 seconds (CLA45 S 4MATIC+: 4.0 seconds), while the basic A45 4MATIC+ model absolves this discipline in 4.0 seconds (CLA45 4 MATIC+ in 4.1 seconds).
The top speed of the basic models is electronically limited to 250 km/h, while the S-models are capable of up to 270 km/h ex factory. With the optional AMG Driver’s Package, the top speed can also be increased to 270 km/h for the basic variants.
Apart from its performance figures, the new engine impresses with its immediate response. To this end the torque curve was carefully balanced (“torque shaping”): The maximum torque of 500 Nm (480 Nm in the basic variants) is available within a range of 5000-5250 rpm (4750-5000 rpm in the basic variants). With this configuration the AMG engineers have achieved a power delivery akin to a naturally aspirated engine.
The engine developers were able to realise a dynamically increasing torque curve in the lower engine speed range, thereby improving throttle response. The increasing torque at higher rpm makes the engine more free-revving. Moreover, the high maximum engine speed (up to 7200 rpm) emphasises the engine’s sporty character.
Engine design
The new engine excels with numerous intelligent design features. Unlike the likewise transversely installed four-cylinder in the 35 models or the preceding model, the new engine is rotated around its vertical axis by 180 degrees. This means that the turbocharger and the exhaust manifold are now positioned at the rear, on the side of the firewall when viewed from behind. The intake system is therefore positioned at the front. This configuration allows the flattest possible and aerodynamically advantageous front section design. Furthermore, the new arrangement allows much improved air ducting with shorter distances and fewer diversions – both on the intake and exhaust side.
One man, one engine
The new engine is entirely assembled by hand. To this end a completely newly designed production line was constructed in the AMG engine manufactory in Affalterbach, where Mercedes-AMG has raised the “One Man, One Engine” principle and Industry 4.0 processes to an innovative level reflecting the latest findings in ergonomics, material flows, quality assurance, sustainability and efficiency. On the road to implementing Industry 4.0, AMG’s hand assembly operation likewise follows the vision of “smart production”.
This excels with maximum flexibility, and is transparent and highly efficient. It safeguards and improves the quality of the engines and production processes using innovative and digital technologies.
AMG SPEEDSHIFT DCT 8G dual-clutch transmission
The 8-speed AMG SPEEDSHIFT DCT 8G dual-clutch transmission likewise contributes to the agile and dynamic character. The gear ratios have been configured so that the driver experiences very spontaneous acceleration in all speed ranges, combined with fast shifting and optimum connections when shifting up. Depending on the selected AMG DYNAMIC SELECT driving mode, the driver receives a specific drive configuration with different accelerator and gearshift characteristics.
Anyone who prefers to change gear for themselves can select the manual transmission mode in every drive program. Using the temporary M-mode, this is possible very rapidly merely by operating a steering wheel shift paddle.
The standard RACE-START function allows maximum acceleration from stationary, a highly emotional experience. This also applies to the drive sound with partial ignition interruption when changing up a gear, and the automatic double-declutching function when changing down. Neither is efficiency neglected: in “Comfort” mode the ECO start/stop function is active; the “gliding” function can be selected in the “Individual” driving mode.
