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 0-62mph time (that for the saloon, with the estate 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.