The Mercedes-AMG 45S is the “Super-sportscar” of the compact class and ranging topping offering from Mercedes-Benz.
With the previous third generation Mercedes-Benz A class getting it’s first taste of the AMG treatment over six-years ago, it was time for the team in Affalterbach to give the now fourth generation A Class a new incarnation. For this we headed to Circuito del Jarama on the outskirts of Madrid, Spain.

Now at Circuito del Jarama we get our first look round the new A45S which is now fitted with the worlds most powerful turbocharged four-cylinder engine, the M139. Producing an impressive 384hp as a “standrard” A45, the A45S manages to output an outstanding 421hp! This is an improvement of 40hp over the previous M133 DE20 LA engine found in the facelift third generation Mercedes A45 AMG, and gives the M139 a output of 211hp per litre which places it on-par with engines you’d expect to find in high class ranges. As with all AMG produced engines, the powerplants found in the A45 are from Affalterbach and adhere to the “One Man, One Engine” principle. The A45S will reach 100 km/h in just 3.9 seconds and will continue on to a top speed of 270 km/h, whilst the standard A45 is 0.1 seconds slower to 100 km/h (4.0) and is electronically limited to 250 km/h, though this can be raised to 270 km/h with the optional AMG Drivers package.
The new engine has been rotated around its vertical axis 180°, meaning the turbocharger and exhaust manifold are now positioned to the rear of the engine bay, allowing for a more aerodynamically and the flattest possible front section of the car. Inside the engine, Mercedes has coated the cylinders with their patented NANOSLIDE technology that is also found in their Mercedes-AMG Petronas Formula 1 engines.
Both variants of the M139 are coupled to the eight speed AMG SPEEDSHIFT DCT-8G dual clutch transmission, which provides shifts in mere milliseconds, and comes equipped with the AMG Performance 4MATIC+ all-wheel drive. Also new for this generation of A45, is Drift mode, which comes as standard with the S and is included in the optional AMG DYNAMIC Plus package on the standard A45. Drift mode is called up when in “RACE” mode when the ESP is turned off and the transmission is in manual mode, allowing for powerslides on any road condition.

Twisting the wheel-mounted driving mode dial round to “Race” and you feel the car tighten up, the exhaust valves open and in general become more aggressive. Opening up the throttle and the power is almost instantaneous, the gearshifts are smooth and lightening quick with a little crackle and pop on every one, or when you lift of the throttle. The steering is light and responsive in conjunction with the Michelin Pilot Sport 4 S tyres, giving you feedback as you go through the corners and making you feel comfortable pushing harder into each upcoming corner.
The AMG Torque Control differential helps to bring the car back around on occasions when you find you’ve pushed a little too hard into a corner, with the font tighten up and the rear being pull round in a “powersliding” style.

Now back in the paddock area we have a better chance to look at the exterior changes on the new A45S. The most striking feature across both variants is the addition of the AMG specific grille on the A Class for the first time. The flared wheel arches and front winglets add to the aggressive look that the contoured headlamps and aerodynamic styled hood give the A45S. This continues round to the side of the car, where the AMG side skirts give the A45S a more road hugging stance, whist the wing mirrors are mounted in a similar fashion to those found on the larger coupes and sportscars. At the rear of the A45S, the thinner rear light clusters help to emphasise a wider rear, with the twin 90mm round exhaust pipes sticking out on both sides of the rear diffuser.
One optional extra that helps that were a big fan of is the AMG Aerodynamic package, which with its modified font splitter, winglets, additional diffuser blade and rear wing help to not only improve that handling abilities of the A45S through improved downforce, but also finish of the aggressive styling of the car. Other options include a range of 19-Inch alloy wheels, the AMG night package or a Silver Chrome package.

Inside the A45S the driver and passenger are seated in sports seats that have a firm lateral support and are covered in black ARTICO man-made leather and DINAMICA microfibre is timeless, and creates typical AMG highlights with double topstitching in yellow. The steering wheel comes in nappa leather/DINAMICA microfibre, with either red, yellow or black stitching, galvanised gearshift paddles nestled just behind it and an adjustable button that allows the driver to set the AMG driving mode without the need to remove their hands from the wheel. As always, the centre console is present in a gloss black finish with a touchpad that is surrounded by additional switches that control the ESP, transmission mode and exhaust mode to name a few.

The MBUX infotainment system has three AMG styles, “Classic”, “Sport” and “Supersport”. When Supersport is selected you get a striking central, round rev countrer and with the other information being moved to the side in a bar form. Mercedes have also added the AMG Track Pace as standard to the A45S, meaning the virtual race engine is fully available through the MBUX infotainment system. By measuring more than 80 different vehicle-specific data channels, the drivers are then able to analyse and improve their driving skills. Another feature of the AMG Track Pace is the ability to record your own circuits into the memory, be it major race tracks famous across the world, or you nearest club circuit, and have the ideal racing line stored and displayed.

Out on the road the ride quality is very good for a “super-sports” compact car, and it’s only when you move into Sport+ and Race that you start to feel more of the road below, it handles the highways with ease and comfort. On the more winding mountainous roads that lead up the Sierra de Guadarrama, the A45S hugs the round, staying planted in the corners with the power coming back smoothly and quickly when you punch the accelerator on the exit.

With their completely re-designed A45 models, Mercedes-AMG has showcased their competence in developing an already class-leading compact into a ground breaking “Super-sportscar” both equally comfortable at highway cruising as it is at windy country roads and race tracks.
Overall the new Mercedes-AMG 45S is a cooling looking, extremely well equipped and punchy compact class car, that has definitely raised the bar in the “Super-sportscar”, compact class market!