Comparison: Mercedes-AMG C43 Vs. Audi S4 Vs. BMW M340i

Comparison / 10 Comments

It's a battle of the go-faster luxury sports sedans from Germany.

Mercedes finally introduced the first all-new C-Class model to wear the famed AMG badge. While we still have to wait for the full-fat 63, the 43's figures already look spectacular.

It may only have a 2.0-liter turbocharged four-cylinder under the hood, but thanks to clever F1-inspired technology and a mild-hybrid system, it produces 402 horsepower and 369 lb-ft of torque. Thanks to Merc's 4Matic AWD system, it can get to 60 mph in just 4.6 seconds.

This car also represents a significant turning point for the AMG brand. AMG's turbocharged four-pot engines have never been used in anything bigger than an A-Class. Anything bigger was blessed with a six- or eight-cylinder engine. How will AMG loyalists respond to this new approach, considering its main rivals still use six-cylinder power? Let's find our in an early comparison between the new C43 and its direct rivals: BMW's M340i and Audi's S4.

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Styling: Subtle Aggression

These three cars represent a middle ground between the standard models within the range and the full-fat performance versions like the C63 (the new one is still on the way), M3, and RS4 (sold in Avant form in other markets). These German blunderbusses have become so powerful that they created a gap in the market for the kind of person who doesn't like to wonder whether they'll make it home alive when the road is slightly damp.

Because you don't get all the power, you don't get all of the ridiculous OTT design elements, and that's not necessarily a bag thing. Styling-wise, the BMW is the least special out of the three, mainly because you can add an M Performance body kit to just about everything these days. Do you have an electric scooter? BMW likely has an M Performance body kit for it.

The S4 and C43 take the same approach. Nothing too wild, but rather subtle hints that boy racers shouldn't even try. The Audi uses various aluminum-look accents, a faux diffuser, a tasteful spoiler, and quad exhaust pipes. Merc uses the same strategy, minus the aluminum accents. Like other AMG products, it has the Panamericana grille so that you can tell it apart from lesser C-Classes.

Front View Driving Mercedes-Benz
Audi
BMW
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Interiors: AMG Sets The Standard

The current BMW 3 Series has now been on sale since 2018, and you can tell. It doesn't have a lousy interior, but it's nowhere near as special as the innards of the C43 and S4. You won't feel short-changed if you opt for the BMW. The quality is still exceptional, and the layout remains brilliant.

Audi's S4 uses the same interior layout as other A4 models, but there are subtle touches that make you want to engage with it. The digital instrument cluster that changes to red when you put it in dynamic mode is a nice touch, as is the flat-bottom steering wheel with perforated leather grips. The faux carbon-fiber trim also looks fantastic.

The C43 gets sportier seats with red contrast stitching, and they look exceptional. The rest is basic C-Class with additional sporty touches like the drive mode select on the steering wheel. It also gets model-specific ambient lighting and faux carbon-fiber trim.

Dashboard Mercedes-Benz
Seat Mercedes-Benz
BMW
2020-2022 Audi S4 Sedan Dashboard Audi

Performance: The Power Of Six

The C43's M139 hand-built (as always with AMG) engine uses an electric exhaust-gas turbocharger borrowed from the F1 team. It also has a belt-driven starter-generator operated by a 48-volt electrical system. The latter can also provide a 13-horsepower boost when you need it. The total power output is 402 hp and 369 lb-ft of torque, suitable for a 0-60 mph sprint time of 4.6 seconds and a limited top speed of 155 mph.

We were expecting it to be faster. The 402-hp output is mighty impressive, so it might just be a case of Mercedes underclaiming and overdelivering. After all, this newfangled four-pot produces more horses than the 5.0-liter E39 V8 M5. Couple that with the standard 4Matic+ AWD system and it should be faster off the line.

Both its rivals are faster, at least on paper.

Mercedes-Benz
Mercedes-Benz
Mercedes-Benz

The S4 uses a turbocharged 3.0-liter V6 engine and it only produces 349 hp and exactly the same amount of torque as the Merc's four-pot. Even with the power deficit, it's faster to 60 mph.

A normal driver wouldn't be able to tell the difference between 4.4 and 4.6 seconds, but those are the figures owners like to brag about when talking about cars. Like the Mercedes, the Audi tops out at 155 mph.

The current-generation M340i is the first M Performance BMW that made us question whether it's worth paying so much more for the M3. The answer is yes, by the way. Still, on paper, it is the fastest. BMW's 3.0-liter turbocharged inline-six generates 382 hp and 368 lb-ft of torque. That's mighty close to the Merc, and you get a much better soundtrack. It will hit 60 mph in 4.1 seconds, and the German fun police also limit it to 155 mph.

BMW
BMW
Audi
Audi

Pricing: Yet To Be Determined

The Audi is the bargain in this group. In Premium trim, it retails for $51,900. The M340i with standard RWD retails for $54,700, and xDrive will cost you an additional $2,000. You'll want to add the xDrive, as this allows it to comfortably outsprint the other two.

Mercedes-AMG has not revealed the final pricing as the car will only be available near the end of 2022. A lot can happen between now and then. That being said, Mercedes has a real chance to upset the apple cart if it gets the pricing right. The C43 may not be a full-fat AMG model, but let's not forget that it's just 50 hp down on the old naturally-aspirated 6.2-liter V8 AMG engine.

The problem is that the average C-Class range pricing ends at a hefty $45,000. Would Mercedes be able to add all these things for just $10,000? It's improbable.

Wheel Mercedes-Benz
Engine Mercedes-Benz
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Audi

Verdict: It Depends On Noise, Probably

The C43's specification sheet makes for good reading. It comes with rear-axle steering, all of the normal AMG driving modes (Slippery, Comfort, Sport, Sport +, and Individual), and adaptive damping. And you can take the top speed up to 165 mph if you pay a bit more money.

Merc's claimed power figures are also impressive, but there's a part of this package that makes us uncomfortable. You have to pay extra for AMG Real Performance Sound, which extracts engine sound and pumps it back into the cabin. Somehow, we can't get over the loss of the six- and eight-cylinder engines. AMG used to be synonymous with V8 engines, and the noises these cars made were just a cut above the rest.

The pre-turbocharged 6.2 V8 was a sonorous beast of a thing, and it felt like it had a soul. It didn't matter that it wasn't as scalpel-like as an M3 because it would grumble angrily at low speeds and refuse to stay in a straight line when the road was wet. It has bucket loads of character, and it remains to be seen if the same is true of the new C43.

Mercedes-Benz
Mercedes-Benz
Mercedes-Benz

We wouldn't bother with the S4 either. It still uses the old 3.0-liter V6 instead of the newer 2.9-liter V6. Thanks to Porsche, we know this is highly tunable and can easily be retrofitted to the S4. The S4 is a brilliant-looking thing, and we love the fact that you can have it in Smurf Blue with red leather seats, but it's just not... fun. Its engine lacks any character and it is dynamically competent rather than involving.

BMW's M340i is hugely appealing. The power output is just 20 hp shy of the C43, but you get that sweet six-pot soundtrack. And let's not forget that it's the only car here that's still available with old-fashioned rear-wheel drive. We still wouldn't buy one because we know that a facelifted model is on the way. It will likely arrive just in time for the first C43 deliveries, scheduled for late 2022.

At the moment, we'd go with the C43, but only because it's the newest.

Mercedes-Benz
Audi
BMW

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