The new Mercedes-AMG compact A 45 4MATIC+/ A 45 S 4MATIC+ are here to reassert their leading positions in their segments. They seamlessly continue the success story of their predecessors, while setting numerous new standards. Available in two output and torque variants, the completely newly developed 2.0-litre engine is the world’s most powerful turbocharged four-cylinder engine in manufactured for series production.
Even the basic model with 285 kW (387 hp) is more powerful than its predecessor. The S-variant with 310 kW (421 hp) jostles with considerably higher vehicle classes. The new AMG SPEEDSHIFT DCT-8G dual-clutch transmission comes with eight gears. The active, fully-variable AMG Performance 4MATIC+ all-wheel drive distributes the power to the rear axle wheel-selectively by AMG TORQUE CONTROL – for top traction and the spectacular Drift mode. This is made possible by a new rear axle differential featuring two multidisc clutches – one for each rear wheel.
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 A 45 S 4MATIC+ requires only 3.9 seconds (CLA 45 S 4MATIC+: 4.0 seconds), while the basic A 45 4MATIC+ model absolves this discipline in 4.0 seconds (CLA 45 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.
The new AMG suspension with specific spring elements and the new, frequency-selective shock absorbers provides the basis for high directional stability and highly dynamic cornering characteristics with low body roll. At the same time comfort has been improved compared to the preceding model. The longitudinal and transverse dynamics are perfectly coordinated. All suspension components have been thoroughly revised in order to achieve a higher maximum lateral acceleration together with easy vehicle control at the limits.
A McPherson strut design is used at the front axle. Suspension is taken care of by one wishbone below the wheel centre, one spring strut and one tie rod respectively. The special axle geometry reduces the influence of the drive on the steering – for high comfort and agile handling. The new wishbone in aluminium reduces the unsprung masses enabling a more sensitive response from the springs. The brake callipers at the front axle are radially bolted – a technology from motorsport for more stability. The front axle carrier is rigidly attached and thus additionally stiffens the front section.
The 4-link rear suspension is likewise rigidly connected to the body via a rear axle carrier, and therefore very torsionally rigid. There are three transverse control arms and one trailing arm plus specific bearings per rear wheel. This design ensures maximum driving stability and agility.
The optional AMG RIDE CONTROL adaptive damping system enables the driver to choose between three different suspension control modes. The spectrum ranges from comfort-focused to sporty. The system operates fully automatically, adapting the damping forces for each wheel according to the driving situation and road conditions. This happens within milliseconds and is infinitely variable, with a wide spread of damping characteristics. The result is that it ride comfort and agility are enhanced in equal measure.
The high-performance braking system ensures fade-resistant deceleration and short braking distances. In the basic models, the 4-piston monobloc fixed front callipers act on 350 x 34 millimetre brake discs, while at the rear axle, 1-piston floating callipers act on 330 x 22 millimetre brake discs. The discs are internally ventilated and perforated to better dissipate heat and prevent brake fading, even with extreme use. The grey-painted brake callipers have white AMG lettering.
The S-models and the basic models with the optional AMG DYNAMIC PLUS package are decelerated by an even larger braking system equipped with 6-piston fixed callipers and 360 x 36 millimetre brake discs at the front. In this case the brake callipers are painted red and bear a black AMG logo. As standard the exhaust system has an exhaust flap which is automatically controlled depending on the engine speed and load. Depending on the drive program selected it modulates the sound from harmoniously discreet (in the programs Slippery, Comfort and Sport) to emotively sporty (in Sport+).
Six driving modes: vehicle characteristics with wide spread: The six AMG DYNAMIC SELECT driving modes “Slippery”, “Comfort”, “Sport”, “Sport +”, “Individual” and “RACE” (standard for S-models, included in the optional AMG DYNAMIC PLUS package for basic models) allow a wide spread of vehicle characteristics, from comfortable to dynamic.
The A 45 S and CLA 45 S even go a step further: yellow highlights reoccur throughout the interior to emphasise the motor racing character of the more powerful models. Also included in the standard equipment are the AMG Performance steering wheel in nappa leather/DINAMICA microfibre with contrasting yellow topstitching, a yellow 12 o’clock marking, AMG steering wheel buttons and AMG logo, plus ambience lighting.
In all models, the centre console in high-gloss black with a touchpad as standard has a further control array with additional switches controlling the 3-stage ESP®, the manual transmission mode and the optional adaptive damping system AMG RIDE CONTROL. In combination with the optional leather package, it features a silver chrome console surround.
The characteristic, sporty AMG ambience is also enhanced by the sports pedal cluster of brushed stainless steel with rubber studs, black floor mats with AMG lettering and a surround in a nubuck leather look, the black fabric roof liner and AMG front entry sills in brushed stainless steel with “AMG” lettering.
The combination of sporty design and sophisticated details is also featured in the MBUX infotainment system with its innovative operating and display concept. MBUX creates an even closer connection between the vehicle, driver and passengers. Emotionally appealing presentations underline the clear control structure and feature brilliant maximum-resolution 3D graphics. Visually, the two displays under one shared glass cover blend into a Widescreen Cockpit and as a central element consequently emphasise the horizontal orientation of the interior design.
The customer can choose between the three AMG display styles “Classic”, “Sport” and “Supersport” for the instrument cluster. The “Supersport” mode is particularly striking with a central, round rev counter and additional information presented in the form of bars to the left and right of the rev counter: with a three-dimensional perspective, they reach far into the background to an artificial horizon.