Newly amped-up AMG C43 begins the performance arm’s transition to electrified four-cylinder power.
We’ve had four-cylinder Mercedes-AMG models since the launch of the A45 in 2013 and, heading further back, rear-driven four-pot performance Mercedes-Benz sedans in the stylish forms of the 190E 2.3-16 and 2.5-16 in the 1980s. But the new C43’s longitudinally mounted turbocharged 2.0-litre engine means it’s effectively crossing the streams, even if it does come with standard four-wheel drive.
The new C43 marks the dawn of a new downsized era for AMG, one that will soon lead to a brawnier C63 plug-in hybrid using a more powerful version of the same base engine.
While the C43 lacks both a charging port and a high-voltage hybrid system, it does bring its own electric innovation with the arrival of a new Garrett 48V turbocharger. This uses a compact motor that acts directly on its shaft, adding up to 6kW of assistance and capable of spinning at speeds to 175,000rpm. It can also harvest up to 4kW of energy from exhaust gas, although more regeneration comes from a 48V starter-generator. Peak system output is 300kW, accompanied by 500Nm of torque.
The electric motor can build boost when there isn’t enough exhaust flowing to help reduce lag and in the car’s more aggressive dynamic modes keeps the turbine spinning in a high-tech form of anti-lag.
Drive is delivered through a nine-speed automatic gearbox that incorporates AMG’s wet clutch, instead of a torque converter, and a 4Matic system with a permanent front-to-rear torque split of 31:69. All-wheel steering is standard, together with active dampers.
Badging aside, the C43’s visual distinction from the regular Mercedes-Benz C-Class is subtle, with just horizontal strakes to the radiator grille, sill extensions and a small wing on the bootlid. A more telling change is the presence of four exhaust tailpipes beneath the rear bumper – slightly over the top for a car with an equal number of cylinders.
If you didn’t know about the C43’s clever new turbo, it would be hard to detect its presence from the driver’s seat. At low speeds, there’s a hint of enhanced induction noise and the new system quickly proves to deliver on AMG’s claim for lag-free responses and ability to maintain boost, even when you lift and then rapidly reapply the throttle.
Engine response is linear throughout the broad power band, although our test car didn’t seem quite capable of reaching the marked 7000rpm redline. Even with manual gear selection, the limiter arrived barely after the 6750rpm where peak power comes.
Yet it’s certainly effective, feeling more than quick enough to bear out the claimed 4.6sec 0-100km/h time (that’s for the sedan, with the wagon only a 0.1sec slower) and with a race-start mode allowing consistent brutal launches.
The C43 lacks the aural savagery that almost all previous AMG models have had as standard. The engine has a pleasing enough note for a potent four-cylinder and with the exhaust in its louder switchable mode still makes some of the pops and gurgles on a lifted throttle, with at least some of these being digitally enhanced through the speakers. But even under full fang, it never grows especially loud in the cabin, and at cruising speeds it fades to near silence.
The ride feels firm at low speeds, regardless of which of the damper-altering dynamic modes the C43 is in – although our test car was riding on the largest available (20-inch) alloys.
Higher speeds and bigger loadings made it feel suppler, handling lumps and bumps with impressive poise, with even the firmest Sport Plus mode not too harsh for road use.
The gearbox is disappointing, though: refined in Drive but pausing for half a second when you request manual downshifts through the steering wheel-mounted paddles. Mercedes engineers say this should be sorted by a software upgrade ahead of sales starting in Australia next year.
The steering is good. Some genuine low-level feedback is allowed to get past the electrical assistance to indicate changes in surface texture. Beyond that, responses are proportional and there’s a well-judged amount of resistance to work against.
Traction is huge and grip is tenacious, with no shortage of adhesion at either end – even when we were tackling twisting French mountain roads in wet conditions.
Although very willing to turn and hold a line, thanks in part to the reduced mass of the new engine, carrying too much speed into the slowest and tightest of corners does provoke the front tyres into surrendering first, the C43 transitioning into gentle understeer.
Yet there’s little sense of the rearward torque bias, even when you deliberately try to provoke a reaction from the back end.
The combination of dynamic virtues feels closer to those you would expect from an S-branded Audi than an AMG from five years ago.
Other comments echo those for lesser versions of the C-Class. The C43’s screen-heavy cabin sometimes feels like it would be better suited to a commercial aircraft’s cockpit than an upmarket sedan and the MBUX operating system often seems excessively complex.
Many functions are duplicated between the wheel-mounted controls and the screen, while others must be dug out of sub-menus. The C43 does get an AMG button as a shortcut to the dynamic functions, at least.
The decision to use identically shaped stalks for both the indicators and wipers combination (on the left) and the gear selector (on the right) is almost guaranteed to cause confusion for anyone coming from a more conventional layout, although one will certainly come accustomed to it.
Overall, the cleaner and greener C43 doesn’t lose out on performance through the transition to four-cylinder power, but the emotional experience is a little diminished from its charismatic six-pot predecessor.
Certainly, plenty of head room has been left for the doubtless more exciting 500kW C63. Given that potential C43 buyers will still be able to choose a hugely talented six-cylinder alternative in the form of the significantly cheaper BMW M340i xDrive, the AMG is facing a potential uphill struggle.
Mike Duff