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.