New Mercedes AMG C43 with the 4-cylinder M139 engine: Review

This is the first time Mercedes has used both port & direct fuel injection in a 4-cyl config. Per litre, it produces more HP than some of the Ferrari V8s & even the Bugatti Chiron.

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Likes

• Engine performance is very good. (2L Turbo, 404 HP & 500Nm)
• Looks good, both inside out. (Distinguishes itself well v/s the regular C)
• Ride comfort (Thanks to the adaptive dampers & soft tubeless Michelin PS4s)
• Handling Performance (Rear Biased 4Matic + Rear Wheel Steering combination works well)

Dislikes

• A feature like Head Up Display is a big miss for a car in this category & price point, Start stop system is very sensitive and kicks in before coming to a complete halt.
• Modification potential is unknown as already a good amount of power has been extracted from this 2L unit.
• Gearbox is not good in city/slow-speed conditions.
• CBU Pricing makes it a tough sell.

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For those who prefer text may read on.

Facts about this M139 Engine

• One man, one engine. (Previous v6 c43 wasn't).
• Most powerful 4-cyl engine in a mass-production car.
• This is the first time Mercedes has used both port & direct fuel injection in a 4-cyl config.
• Per litre this engine produces more HP than even some of the Ferrari's V8 & even the Bugatti Chiron.
• The twin-scroll turbocharger is new and fitted with roller bearings for the first time, reducing mechanical friction so the turbo can spin more easily.
• For a big boost small displacement engine, the challenge was to keep everything cool so for that Mercedes went in for a 3 systems Cooling (Air, Oil & Water).

Driving Performance

So let's just address the Elephant in the room first. Yes, the C43 AMG is a 4-cylinder, so what? The best of cars we know and have idolised over the past years have also been 4 cylinders. Some examples and start off with Mercedes, the 190E which is sort of considered to be the forefather of the performance range C Class we know was a 4-cylinder. In fact that 2.3 L engine was simply fantastic in its base form too, but then Cosworth came along and gave it 50 more HP with some lightweighting and dual overhead cams & made the 190 E legendary. In fact, some race versions are known to produce more than 300 HP+ easily from a 4cyl.

The Mitsubishi Evo Range. Which we all LOVE were great cars, Again 4 cylinder engines. Even the original M3 (E30) was a 4cyl.

Ok, now let's not forget this is not the C63 we are talking about, hence it's not lost a V8 in favour of this engine but the V6 which was anyway not that great of a performer. The V6 had an aural advantage over this engine for sure, but was it the best V6? Maybe not, but the M139 might be the best 4cyl in production.

Overall this is a very smooth engine for a 4cyl, cleanly pulls to the redline. The refinement is also very good. Exhaust sounds good for a 4cyl, also the sounds pumped in the cabin are actual and not fake because there's a mic connected to the exhaust playing the exhaust notes in real-time via the speakers, Not bad. The gearbox is a 9-speed multi-plate clutch (wet) transmission, good to drive fast but not so good at city/traffic speeds. I personally felt that the upshifts were better than the downshifts. Yes, there's also a 48V hybrid motor, but that just gives momentary boosts upto 14-15HP I believe, and would be more of a contributor during coasting etc for better FE & emissions.

Handling Performance & Ride Quality

Speaking good things about the engine but if that's the case a lot may think that why don't we just buy the A35 AMG (has 2L Turbo M133 block) because that's cheaper or better buy the A45 S (same M139 block) as that's faster, well this is where this car offers a more engaging driving experience, is that all those AMG's which I just mentioned are front biased all-wheel drives, whereas this is the one which is REAR biased & not only that it has rear-axle steering too which contributes greatly towards the handling dynamics. The lane changes require lesser inputs, overall would be fun in the twisties too. Interestingly despite the rear bias (31 - 69 spilt) 4Matic the car on very few occasions felt rear-led traction. Contributing factor to that may be these adhesive-like tyres.

Yes, the car comes OE fitted with the Michelin Pilot Sport 4S.

Personally, I feel the C43 didn't require to be a 4matic, could have launched an RWD only to target more fun factor and let the C63 be a 4matic.

Coming to the ride quality, which thanks to the adaptive dampers was very good for cruising in Comfort Mode. Yes, as soon as you switch to Sport then the low-speed ride is very stiff. Note that the suspension doesn't lower. Tyres too contribute here in cushioning the ride. During tests the tyre pressure was around 40 PSI, hence I believe that by lowering the pressure there is still scope for improvement in the ride even further.

Exterior & Interior Looks

I have always preferred the C43 sedan body shape over the coupe & in this gen of the C43, the 43 AMG treatment works really well.

The body kit is aggressive enough to distinguish itself from the regular C Class range, particularly from the rear thanks to the antagonistic diffuser design;

The interior fit & finish is properly good, looks well put together.

Love the steering wheel which feels great to hold and achieves good haptics, speaking of haptics the paddle shifters are SOLID metal pieces, very intuitive to operate as well.

Red seat belts always remind you that this is a more serious version of the C Class.

But where is the Coupe?

Usually, in Mercedes product launch timelines the sedan arrives first and then the coupe follows, but this gen C has been there for a long time but still, there's no sign of the Coupe, so what's happening?

Well, my theory is that there's a new product by the name of the CLE which is sort of a combination of the C Class and the E Class Coupe.

And I think the above model will stand as a common coupe for both the C & E, not sure when it will launch in India though.

Final Thoughts

In India, the Mercedes-AMG C43 rivals the BMW M340i which is priced (& sells) very well as it's a CKD.

This engine & kit work for the C43 really well but the problem is that it shouldn't have been put in the C63 & it seems Mercedes has finally recognised that & soon (C Facelift onwards) will offer the C63 with a V8.

The previous gen W205 C43 had the V6, which was good but may not be remembered as the best V6. This gen W206 C43 lost 2cyls but this engine may be remembered as one of the best 4cyls ever made.

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