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.

Newturbocharged 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 powerfulturbocharged four-cylinder manufactured for series production. Mercedes-AMG hasbettered the output of the preceding engine by 30 kW(40 hp).

Maximum torque has also increased from 475to 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 manywell-known super-sports car engines. The new, highly efficient powerpack isproduced on an innovative production line in Affalterbach, on the “OneMan, One Engine” principle.

Inthe 45 models

The four-cylinder ensures extremely agileperformance in two output classes: with 310 kW (421 hp) as the S-model and with285 kW (387 hp) in the basic version.

This positioning logic has already provedsuccessful for the AMG Performance models with a V8 engine, and meetsindividual customer wishes even better. The new compact sportscars absolve thesprint from zero to 100 km/h in record time: the A45 S 4MATIC+ requires only3.9 seconds (CLA45 S 4MATIC+: 4.0 seconds), while the basic A45 4MATIC+ modelabsolves 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 newengine impresses with its immediate response. To this end the torque curve wascarefully 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 AMGengineers have achieved a power delivery akin to a naturally aspirated engine.

The engine developers were able to realisea dynamically increasing torque curve in the lower engine speed range, therebyimproving throttle response. The increasing torque at higher rpm makes theengine more free-revving. Moreover, the high maximum engine speed (up to 7200rpm) emphasises the engine’s sporty character.


The new engine excels with numerousintelligent design features. Unlike the likewise transversely installedfour-cylinder in the 35 models or the preceding model, the new engine isrotated around its vertical axis by 180 degrees. This means that theturbocharger and the exhaust manifold are now positioned at the rear, on theside of the firewall when viewed from behind. The intake system is thereforepositioned at the front. This configuration allows the flattest possible and aerodynamicallyadvantageous front section design. Furthermore, the new arrangement allows muchimproved air ducting with shorter distances and fewer diversions – both on theintake and exhaust side.

Oneman, one engine

The new engine is entirely assembled byhand. To this end a completely newly designed production line was constructedin the AMG engine manufactory in Affalterbach, where Mercedes-AMG has raisedthe “One Man, One Engine” principle and Industry 4.0 processes to aninnovative level reflecting the latest findings in ergonomics, material flows,quality assurance, sustainability and efficiency. On the road to implementingIndustry 4.0, AMG’s hand assembly operation likewise follows the vision of“smart production”.

This excels with maximum flexibility, andis transparent and highly efficient. It safeguards and improves the quality ofthe engines and production processes using innovative and digital technologies.

AMGSPEEDSHIFT DCT 8G dual-clutch transmission

The 8-speed AMG SPEEDSHIFT DCT 8Gdual-clutch transmission likewise contributes to the agile and dynamiccharacter. The gear ratios have been configured so that the driver experiencesvery spontaneous acceleration in all speed ranges, combined with fast shiftingand optimum connections when shifting up. Depending on the selected AMG DYNAMICSELECT driving mode, the driver receives a specific drive configuration withdifferent accelerator and gearshift characteristics.

Anyone who prefers to change gear forthemselves can select the manual transmission mode in every drive program.Using the temporary M-mode, this is possible very rapidly merely by operating asteering 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.