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The all-new Mercedes-AMG tuned C-Class Coupé represents a big challenge to the likes of the BMW M4, Audi RS5 and Lexus RC F at the top of the power spectrum and the BMW 440i and the Audi S5 at the lower end.

Following on from the recently introduced C 63 saloon and estate, the range-topping C 63 variants eschews its predecessor’s highly rated naturally aspirated 6.2-litre V8 engine for a smaller and more efficient twin-turbo 4.0-litre V8 - essentially the same unit used by the company’s GT performance flagship.

In standard C 63 Coupé guise its hand assembled engine produces 469bhp and 479lb ft. In the headlining S Coupé model driven here, though, the 90deg V8 receives additional boost pressure as well as detailed changes to the inlet manifold and dynamic engine mounts that vary in stiffness depending on revs. There is also an Edition 1 version of the C 63 S Coupé also.

The result is a further 34bhp and 37lb ft, endowing the range-topping model with a sturdy 503bhp at 5500rpm and 516lb ft on a band of revs between 1750 and 4500rpm – exactly the same power but 37lb ft more torque than that offered by the Mercedes-AMG GT S.

It also betters the M4 by 78bhp and 111lb ft, the RS5 by 89bhp and whopping 199lb ft and the RC F by 33bhp and 125lb ft. Propping up the AMG range is a breathed on version known as the C 43. Built by Mercedes-Benz and using components developed by AMG - the C 43 uses a smaller 3.0-litre V6 to propel itself producing 362bhp.

The reserves are fed through the latest incarnation of AMG’s seven-speed Speedshift MCT dual-clutch automatic gearbox, which operates in combination with a mechanical locking differential in the C 63 Coupe, but in the C63 S Coupé it comes allied to an even faster reacting electronic locking differential.

The driver can choose between four different driving modes on the C 63 Coupé and up to five on the S model, while the switchable electronic stability control system offers three settings: On, Sport and Off.

The styling of the latest C 63 Coupé is significantly differentiated from standard versions of the new second-generation C-class Coupé. The only exterior elements shared between the two cars are the frameless doors, roof and boot lid. The remainder is unique.

The wider body has been developed to house a largely bespoke chassis featuring tracks that are increased in width by 73mm at the front and 46mm at the rear over the standard C-Class Coupé at 1636mm and 1592mm respectively. Wheels sizes vary according to model, with the new C 63 receiving 18in rims and the C 63 S running on 19ins.

Overall, the new car is 45mm longer, 107mm wider and 12mm higher than before. Crucially, it also rides on a wheelbase extended by 75mm over that of its predecessor, endowing it with added exterior space if not a larger boot, which at 355 litres in capacity is 95 litres less than before.  

As for the standard equipment - the C 43 includes a wealth of standard equipment as found on the lower spec models of the coupé and cabriolet, including sat nav, reversing camera, leather upholstery etc. There is also the addition of an aggresive bodykit, 18in AMG-badged alloys and a performance exhaust system.

Upgrade to the C 63 and you'll find Mercedes COMAND infotainment system, LED headlights, sports seats, an more aggressive bodykit, a mechanical rear axle differential lock , and electrically adjustable front seats. While the C 63 S not only gains more power but 19in alloy wheels, red brake calipers and interior ambient lighting as well.

The C 63 Edition 1 car is inspired by Mercedes-AMG DTM race car, which means that it rolls on 19s at the front and 20s at the rear, a redesigned front splitter and aerodynamic bodykit, a Burmester sound system and numerous black gloss exterior trim.

The C 63 S Coupé is a different proposition to its predecessor but no less exhilarating on the right road. The big bore brawn of its old naturally aspirated engine has been confined to history, replaced by the more frenetic fervour of its new turbocharged powerplant.

Despite giving away more than 2.0 litres in capacity to the car it replaces and bringing an extra 70kg in kerb weight due to the increase in overall dimensions, it is still ferociously fast. Mercedes’ figures suggest the new C 63 S Coupé will accelerate from 0-62mph in just 3.9sec, making it faster than any of its rivals by some margin. With the optional AMG driver’s package, it’ll also run to a limited 180mph.

With a big lift in torque, the new engine brings added flexibility and performance. Its stout 516lb ft endows it with both greater speed out of the blocks on a loaded throttle and a more relaxed demeanour when cruising on lighter loads.

The delivery is extraordinarily linear for a forced-induction engine, giving it genuine character. Work it hard and it will spin to 7000rpm before the onset of the limiter. AMG has also exceeded in providing the C 63 S Coupé with a wonderfully hardcore exhaust note.

While the engine continues to dominate the driving experience, the gearbox now provides more enthusiastic support than ever before. In Comfort, there’s added smoothness and a crisper action on part load when used as an automatic. In Sport Plus the upshifts are wonderfully determined on a wide open throttle in manual mode, and crucially there’s added subtlety in the way it goes about its business when you’re hauling big revs.

The biggest difference, though, is the ability of the gearbox to provide more accommodating downshifts than in the past. Pull the left-hand paddle and it’ll now drop up to four ratios to within 1000rpm of the redline. In combination with the dynamic engine mounts, the improvements brought to the operation of the gearbox help reduce driveline weight transfer, making this latest AMG model more stable on entry to corners as you drop down the gears and get on the brakes.

There is a lot to like about the car’s dynamic characteristic, although its ultimate ability is determined by the driving mode you engage. In Sport Plus, the steering is both weighty and feelsome, instilling confidence the moment you set off. It is also very direct and consistent, which allows you to place the new two-door with real conviction.

Out on the open road, the latest AMG model proves alluringly fluid when pushed hard, offering up truly determined turn-in traits and exemplary body control. Superb balance and an abundance of grip allow you to carry big speeds into corners before exploiting the sheer explosiveness of its engine with a dose of throttle on the exit. It is extremely trustworthy and sufficiently alert in its actions to instantly communicate any breach of adhesion.

If you leave the stability control in its normal setting, you’re ultimately treated to a touch of understeer when grip is exhausted, making it wonderfully forgiving when you overstep its dynamic boundaries. By switching the electronic safety net off completely you can enliven the tail in the best of C 63 traditions – and with tremendous confidence, because the new model is superbly controllable on the throttle. The efforts of the electronic differential also provide terrific drive out of corners, allowing you to get on the gas early and without the need to be overly subtle in your actions. 

But while the C 63 is now more communicative and controllable than ever, it’s also a good deal firmer at the extremity of its suspension settings. In Comfort, there’s sufficient compliance to allow it to soak up broken or patchworked bitumen. However, the ride becomes quite harsh in Sport Plus, with aggressive rebound properties sometimes leading to unsettling vertical movement.

It is fine on a race track, but the rawness can become issue on undulating back roads, where it tends to hop around more than the driver would like. Moreover, the chassis is extremely sensitive and channels a great deal of road noise into the cabin on coarse surfaces.

The underlying  firmness and sensitivity is at the centre of efforts to endow the C 63 Coupé more consistent and controlled on-limit traits.

There is no doubt that it operates on a higher level and is a more engaging car than the one it replaces. But the constant road shock that enters the cabin in Sport Plus mode can make it draining over extended distances. All of which makes it a relief to know you can simply switch it back to Comfort and enjoy the subtlety of less aggressive suspension settings when you wish. With this broadness of ability, AMG has covered just about every base.

It may have abandoned its highly regarded naturally aspirated engine for a contemporary new turbocharged powerplant, but the C 63 Coupé is now a more exciting car to drive than ever before – at least in range-topping S guise, as tested here. With a largely bespoke chassis, it also offers a more visceral driving experience than its predecessor. The progress is perceptible in just about every area of its dynamic ability.

The aggressively styled two-door also provides a broader dynamic repertoire than before, making it both a more amenable proposition in town and more enjoyable out on the open road. Added to this, the new Mercedes-AMG offers improved accommodation and a level of perceived cabin quality to shame some competitors. If you cherish your driving, it should definitely be on your shortlist. 

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