Mercedes-AMG C43 2023 review

At $134,900 before on-road costs, the four-cylinder 2023 Mercedes-AMG C43 is nearly 20 percent more expensive than the previous-generation, six-cylinder version.

It’s more expensive, but this year’s all-new C43 is also a better-looking sports sedan. At 300kW, it’s more powerful – despite dropping two cylinders and a litre of capacity in the name of reduced emissions – and standard specification is even higher.

However, such an ambitious price increase, especially in the presence of more affordable rivals, including the refreshed-for-2023, straight-six BMW M340i LCI ($104,900), and the V6 Audi S4 ($106,200), has set hopes very high.

Just like with the previous shape, the C43 is the junior of the two true-AMG versions of the C-Class. In latest-generation ‘W206’ form, both the C43 and C63 will be four-cylinders – not V6 and V8 as the pair was in the past.

A plug-in hybrid system will see the latter car pump out peak power of 500kW in optimal conditions, while the plugless C43 produces 300kW whenever you ask it to. In some ways, the uncomplicated (and much lighter) C43 has carried higher expectations – especially because of the source of its engine.

A45-sourced engine is capable, but produces middling 0-100km/h result

Pulled straight from the acclaimed A45 super-hatch – then turned sideways for the C-Class’s longitudinal layout – the 2.0-litre ‘M139’ turbo four-cylinder engine’s response is impressive in an A-Class shell, where its spits out 3.95 sec 0-100km/h times as tested.

However, the 1856 kg C43’s additional 221 kg of weight – and the slightly decreased state of tune (down 10kW, to 300kW, while torque is steady at 500Nm) – results in more sluggish performance in the sedan.

Despite the use of an electrically-assisted Garrett turbocharger, which skirts lag by using a motor to spool the turbo almost immediately, a marginal lack of low-end torque and hesitant first-gear engagement from launch meant we could only achieve a 4.65 sec 0-100km/h time.

We almost matched AMG’s claim of 4.6 sec – itself 0.1 sec quicker than the old V6 C43 and the S4 (4.7 sec), but BMW says its M340i can do the baseline 0-100km/h sprint in 4.4 sec – and independent tests confirm it can actually do the sprint, stock, in less than 4.1 sec.

It feels reasonable to label the new C43’s performance middling. Theoretically, the plug-in hybrid C63 should smash it – when there is sufficient charge in that car’s battery – as AMG claims it cuts the time to triple digits to just 3.4 sec.

The C43 can be rewarding, but only when driven very hard

Ironically, though, it’s in these hard-acceleration moments where the C43 feels at its best, with no confusion about the driver’s intention: full chat, where the engine we know can be brilliant comes alive and the racy multi-clutch transmission slickly slices gears together with a raucous crack between ratios.

We also loved the C43’s agility. Despite being about 100 kg heavier than the old six-cylinder model, the move to a four-cylinder engine reduces load over the front axle, letting the C43 really dive into corner apexes with zeal.

Plus, the four-wheel steering is one of the best-tuned on the market, subtly tightening your line without being overwhelming.

Like the previous model, the C43 has all-wheel drive, though this is tuned for safety and outright speed, not for fun. The ratio is, unusually, fixed – at 69 percent rear, 31 percent front. Like the rapid Audi S4, it’s quite difficult to induce slip to the C43 in the way a BMW M340i will happily rotate despite the fitment of AWD to that car.

C43’s highly-strung character won’t be for everybody

Unfortunately, that moment of clarity when driving the C43 hard never happens when driving in a less hardcore way. In any other driving situation, the junior AMG C-Class is, at times, remarkably amateurish in execution. Often it is simply not premium.

In our opinion, the brief for a circa-$130,000 luxury-sports sedan like the AMG C43 is to be an executive express that’s capable of sledgehammer performance one day and supple-riding subtlety the next. The M340i and S4 – and even much quicker cars like the Alfa Romeo Giulia Quadrifoglio – are capable of this split persona.

The C43 is not. It is as if its engineers primed it to be raring to go at all times, and to be distinctly sulky if you won’t grab it hard by the reins and floor it.

This sedan is stiff-riding, loud (but in a droning sense), and highly-strung – to the max.

Severe transmission harshness at low and moderate speeds

The 2.0-litre engine and nine-speed multi-clutch automatic are an unhappy partnership at slow and moderate speeds, demonstrating lethargic low-end engine response and appalling transmission shunt that should never have left the proving ground.

Take a common situation driving in the suburbs. You accelerate the C43 from a stop up to 60km/h, but you need to slightly reduce your throttle input because of the way other cars are moving around you. Lifting too urgently can return fore-aft jerking motions unless your inputs are perfectly measured.

The C43 can’t do this smoothly. You partially lift the throttle, gently – and the car violently and suddenly lets a clutch out all the way, jerking the body back and forth in an unacceptably uncouth manner – and leaving your passengers asking what you’ve just done– even in comfort mode, where the powertrain character ought to be rounded and user friendly.

In anything other than sports-plus style driving, attacking a country backroad or track, the C43’s transmission calibration is so poor that it can make the car uncomfortable and awkward to drive. But with a moderate throttle, just why this MCT design – that replaces the torque converter with a clutch pack – nips and clunks on down changes is a real head-scratcher.

The automatic’s poor tuning will be quickly noticeable on a test drive, and it compares poorly to the smooth eight-speed torque-converter autos used by the M340i and S4 – not to mention the regular auto used by the non-AMG C300 that isn’t much slower than the C43.

Volkswagen’s early DSG dual-clutch automatic transmissions were rightly criticised for their lack of refinement. The C43’s multi-clutch unit makes those decade-old Volkswagen gearboxes seem quite polished.

Perhaps it’s simply an unhappy powertrain marriage, the low-rpm characteristics of the electro-induced forced induction at odds with 9G MCT transmission selected to fit the longitudinal driveline application. But it lacks the cleanliness and polish, by some measure, of the vastly more resolved A45 stablemate with essentially the same engine.

Sometimes, a certain engine/transmission calibration is necessary to improve fuel economy, to match strict European emissions regulations. If that was the goal, the result is eyebrow-raising: the C43 consumed 14.1L/100km on our mixed fuel economy test loop. The old V6 model delivered the same – sometimes a bit better.

Very stiff ride quality fails to match suppleness of rivals

The foibles don’t stop there: another factor punters will pick up on within seconds of commencing a test drive on Australia’s broken urban roads will be the C43’s compromised ride quality.

Some firmness is expected in a sports sedan, but the C43’s brittle and at times poorly-controlled ride is baffling because we know how solid this platform can be. We run a C200 Edition C long-term test car, and this delivers a consistently supple, buttery ride.

As is common, a decision was made to equip the Australian-spec C43 with the biggest available wheels and tyres – good-looking 20-inch snowflake-style aero wheels that in many ways complete the car’s strikingly handsome exterior design.

But the 20s leave room for a licorice-thin tyre that can’t give the chassis much by way of bump insulation. And this didn’t need to be done: while the German-spec C43 rides as standard on pedestrian-looking 18s, a set of great-looking 19s is available. This compromise size might have been ideal.

The suspension is stiff, as many would expect from a true AMG product, and features the brand’s steel-type ride control feature with two-mode adaptive dampers with comfort and sport profiles.

Comfort can’t dial out the brittle ride and ever-present slap across sharp road imperfections informed by the huge wheels and low-profile tyres, sending even moderate hits from expansion joints rattling through the cabin plastics – but this softer mode introduces poor vertical body control with a subtle pogoing of the chassis that is an odd combination with the stiff ride.

Switching the dampers to sport mode is something of a solution: it makes the ride even harder and less luxurious, but at least the body control is brought completely in check. If you’re going to be uber-stiff, at least be uber-controlled too.

In a way, this reminds us of a similar (but less pronounced) problem with the adaptive dampers that are optional on the non-AMG C200 and C300 models. This optional suspension feels suspiciously like that of the C43: boaty in comfort, brittle in sport – but these characteristics get worse in the C43 and are compounded by larger wheels.

Whichever damper setting you choose, road imperfections are never thoroughly filtered out and the fizzy and noise penetrates into the cabin ambience far too frequently and loudly.

As what’s presumably the more tempered of two AMG C-Class options, the C43 genuinely lacks the sort of family-friendly pleasantry a good many potential buyers might expect.

As an aside: the C43’s suspension makes us wonder just how hard the incoming C63 will be.

Because the C43 isn’t supposed to ride like a C63. This car needs to be more like a velvet dagger, in our eyes, all suppleness and compliance, pleasing to observant passengers and driver alike over different surfaces – and not just because compliance makes cars quicker. The C43’s ride never fades into the background like it should.

We suspect the parameters for the C43’s stiffness have simply been dialled up into a territory designed to please people upgrading out of the amazingly capable – but never relaxed – A45.

If so, that might be a sound decision, but we suspect that upgraders coming out of AMG’s beaut hot hatch might be reaching a stage of their life where they want more compliance and smoothness from the engine, transmission and suspension. Perhaps there’s a baby seat to fit in the back seat.

Lots of noise from rattles and creaking reduces luxurious nature

Further, the stiffness introduced to the W206’s otherwise peachy chassis by the C43 pushes the new C-Class’s body past what it seems to want to accept.

Our Patagonia red test car exhibited such loud and groaning creakiness on any occasion the body flexes – entering or exiting driveways, tuning into sloping streets – that it sounded more like a car with 200,000km on the clock than its 2000km.

As one Chasing Cars’ reviewer put it, it’s like our test car had bags of marbles inside both front doors that jiggle about constantly.

That’s a shame, because the C43’s interior – shared in almost every way with the C200 and C300 models, down to having comfort seats as standard – is a pleasant place to be.

Those seats are supportive, the nappa steering wheel feels great in hand, and the impressively bright screens worked perfectly with wireless smartphone mirroring.

Mercedes’ latest-gen cabin technology is emerging as one of the more usable systems out there – though the Burmester stereo requires extensive tweaking through the EQ screen to bring out its high fidelity.

The sedan’s back seat and boot are also spacious and usable – though the decision to abandon the wagon version of the W206 C-Class for Australia limits the practicality factor somewhat.

The safety assistants generally worked well, with subtle lane keeping and smooth adaptive cruise control functions – with the exception being one unsettling false-positive that saw AEB apply 100 percent braking force to the shock of the motorist behind us.

The honest verdict on the C43

Between the car creaking out of our driveway and the interior plastics rattling across virtually every bump, owners would be right to question the build quality. In reality, it’s just too stiff.

Our far more relaxed and comfortable C200 long-term test car, with soft suspension, smaller 18-inch wheels and chunkier tyres, has no such issues.

But nor have any of the several examples of Audi S4 or BMW M340i that have come through our garage. It is possible to attain high performance in a sporty, luxurious sedan without resorting to pushing rigidity past the point where the chassis is clearly saying – in groaning metal and glass – “enough!”.

In our view, the C43’s rough transmission calibration, stiff-legged ride and groaning body means the brief has been comprehensively missed. What should be a supple, slick foil to the C63’s acknowledged hardcore manner instead feels like a slow imitation of that car, seriously lacking polish.

Maybe this has happened because the A-team engineers from Mercedes-Benz and AMG are likely hard at work on the brand’s first fully-electric C-Class – a behemoth project set for release in 2028, leaving the partially-electrified W206 models as, perhaps, a rushed stop-gap.

But what the C43 feels like is that the development program stopped after the sedan was injected with spice lifted from the A45 rack, and that little subsequent attention was paid to maintaining time-honoured C-Class hallmarks of refinement, core integrity and quality.

This reaction couldn’t be more different than the universal response of the Chasing Cars team to our C200 Edition C long-termer, which continues to rate very highly – perhaps best in segment – for ride quality, refinement and polish at the circa-$80,000 price point.

That’s why we want to make clear that this is a C43 problem, not a C-Class problem. We find the C200 genuinely likeable and the C300 is very liveable – if you avoid the adaptive dampers.

We now await the arrival of the new C63 to see whether that vehicle – which expands on similar bones to the C43, albeit with the addition of a high-performance PHEV system – is more rounded in terms of its execution.

But when it comes to the C43, in the presence of two great rivals in the M340i and S4 – both having retained their six-cylinder engines, supple damping and seemingly superior quality standards – while being nearly $30,000 cheaper – it’s a simple verdict. We would suggest buying one of those instead.