Mercedes-Benz has launched the AMG-lite version of its new C-Class sedan, the Mercedes-AMG C43. It slots in between the standard C-Class and the full-blown, high-performance AMG C63. The big news is its engine—a 2.0-liter, turbocharged, mild-hybrid, hand-built four-cylinder that makes 402 horsepower and 369 pound-feet of torque. Internally known as the AMG M139, it’s borrowed from a handful of other AMG models including the new SL43 and it gets all of the same clever tech.
Just as it does in other models, the AMG M139 engine in the new C43 uses 48-volt mild-hybrid technology to improve both performance and fuel efficiency, with an emphasis on the former. It’s the first production car engine to use an electric exhaust-gas turbocharger, which can provide boost at virtually idle. This improves response, reduces turbo-lag, and increases power lower throughout the rev range.
The electric exhaust-gas turbo features a 1.6-inch thick electric motor nestled on the turbocharger shaft, in between the exhaust-side turbine wheel and the intake-side compressor wheel. Typically, exhaust gases alone power turbochargers but the electric motor initially powers this one, which allows for a more instantaneous response before the exhaust gasses take over.
Additionally, this four-pot gets a two-stage fuel injection system. The first stage uses precision piezo fuel injectors, which can deliver fuel at 2,900 psi. The second stage is a manifold-port-injection setup, which allows for the engine’s high specific power output.
This all results in a 2.0-liter turbo-four that makes 402 horsepower and 369 lb-ft of torque. It gets paired with Mercedes’ own nine-speed automatic, which ditches the torque converter, replacing it with a wet-clutch for reduced weight and improved throttle response. According to Mercedes-AMG, the C43 can hit 60 miles per hour in 4.6 seconds and go on to a top speed of 155 mph. If you opt for either the 19- or 20-inch wheels, though, that top speed bumps up to 165 mph.
In addition to the electric turbo, the AMG M139 also gets a belt-driven starter-generator (RSG), which can add 13 horsepower while also improving efficiency. One of its functions is to allow the car to glide a bit while using auto start/stop to help smooth the transition.
As per usual with Mercedes-AMG products, there are several different drive modes that change certain characteristics of the car: Slippery, Comfort, Sport, Sport+, and Individual. The latter is where you can adjust the car’s aforementioned “Glide” function.
Of course, in keeping with the rest of Mercedes’ brand strategy, the new C43 is exclusively all-wheel drive. The AMG 4MATIC all-wheel drive system features a fixed torque split—31 percent to the front axle and 69 percent to the rear axle, giving it a rear bias for better handling.
The Mercedes-AMG C43 rides on steel springs with adaptive dampers. Those dampers are adjusted by the different Dynamics Select settings, which can be finely adjusted in its Individual setting. AMG 43-specific front steering knuckles, suspension joints on the spring control arm, and elasto-kinematics are supposed to ensure a sportier driving feel.
AMG also tweaked the steering rack itself, giving it a variable-ratio geometry, which adjusts to each different drive mode, as well as variable power assist, which increases at low speed but decreases at high speed. The idea is to offer light, easy steering when maneuvering in parking lots but meatier, more direct steering while on the highway.
The Mercedes-AMG C43 also gets rear-wheel steering, which is a first for the C-Class and unusual on such a small car. At speeds under 37 mph, the rear wheels will turn opposite the fronts up to 2.5 degrees but will turn in the same direction as the fronts at speeds above 37 mph, by up to 0.7 degrees. When turning opposite the fronts, rear-wheel steering effectively shortens the wheelbase, providing a tighter turning circle and more agile feeling steering. However, at higher speeds, when turning in parallel with the front wheels, it provides better stability.
To slow it all down, the C43 gets 370 x 36 mm discs and six-piston calipers up front, with 320 x 24 mm discs and single-piston calipers out back. The calipers come painted silver as standard, with black AMG lettering.
Aesthetically, the Mercedes-AMG C43 distinguishes itself from the standard C-Class with an AMG-specific grille featuring chrome vertical grille struts, a new front bumper, more aggressive air intakes, and quad exhausts pipes out back. From the looks of it, those exhaust pipes are the real deal, which isn’t a given with Mercedes anymore..
Inside, the C43 gets sportier seats covered in MB-Tex/Microfiber with contrast stitching and a flat-bottom AMG Performance steering wheel that’s wrapped in Nappa leather and Alcantara, plus aluminum paddle shifters. Carbon fiber inlays replace all of the normal C-Class trim, too. The 12.3-inch MBUX infotainment system, 11.9-inch digital gauge screen, and the optional head-up display get some AMG-specific menus and graphics, as well. Rounding out its interior functions is an AMG Track Pace data logger, which can record more than 80 car-specific data points, such as speed, acceleration, g-force, steering angle, and braking.
The highlight here is the engine, though. Thanks to it, the C43 immediately becomes the most powerful car in its class, with its competitors such as the BMW M340i (382 horsepower), Genesis G70 3.3T (365 horsepower), Cadillac CT4-V (325 horsepower) and Audi S4 (349 horsepower) all making less power from similarly sized, or even larger, engines.
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