Third gear. In the new C 63 S Coupe there are two ratios before it and four after, but it’s not until Third where you feel all the mighty thrust of its twin-turbo V8 engine.

Reaching third gear under full throttle is pretty hard to achieve cruising Kings Cross on a Saturday night or idling along Parramatta Road five days a week, like how many AMGs sadly spend their time.

It’s also impossible to savour legally unless you’re on the hallowed stretch of derestricted Stuart Highway north of Alice Springs, or on a racetrack like we thankfully were at the C 63 S Coupe’s Australian launch.

In the first two gears, the new Coupe feels as darn quick as we’ve come to love from the existing C 63 S sedan and Estate, but from Third onwards, the engine fully wakes up to remind you that 375kW and 700Nm really are very big numbers for a mid-sized car. Its machine gun with diarrhea exhaust note is merely the start of the story.

2016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 12016 Mercedes-AMG C 63 S Coupe Edition 1

Like the sedan and wagon, the new two-door Coupe only comes to Australia in hepped-up C 63 S guise, with an extra 25kW and 50Nm from the 4.0-litre twin-turbo V8 over the regular C 63 that Australia doesn’t get for this generation.

Unlike the sedan and wagon, the Coupe gets a 24mm lower proper performance-car coupe profile which looks almost Porsche-like from behind.

Adding further credence to the AMG Coupe are bulging rear wheelarches to match the fronts and wheels that are half an inch wider on the front, and a whole inch wider on the rear.

This pushes the front track 27mm wider than the C 63 S sedan and 46mm wider on the rear, but the 20-inch rear wheels are also an inch bigger in diameter like a hot rod or a fully-fledged supercar.

Tyres are also wider by 10mm on the front and 20mm on the rear, with 255/35ZR19 and 285/30ZR20 in either Continental Contisportcontact 5 or Michelin Pilot Super Sports fitted to our test cars.

The C 63 S Coupe is also treated to all the other trick bits from the C 63 S sedan and wagon, including the seven-speed AMG Speedshift multi-clutch auto, electric locking rear diff, high-performance steel brakes, adaptive dampers and numerous bespoke suspension components.

It’s 0.2s faster than the BMW M4 to the metric tonne.

On the inside, the Coupe also gets the same butt-hugging front seats with seat heaters and Nappa leather, panoramic sunroof, AMG-specific heads-up display and TV built into the multimedia system.

Despite losing two doors the Coupe is actually 70kg heavier than the sedan, but uses unique gearing and its extra rubber to shave 0.1s from the 0-100km/h sprint to result in a Ferrari F40–like 3.9 seconds. Third gear proves this is of little relevance though, and the ferocious pace at which it charges toward its 290km/h limited top speed is a far greater feat.

Those coupe looks and that 0.1s of acceleration will cost you $7890 more than the sedan at $162,400. More significant is the $12,500 more the coupe costs than its closest rival in the BMW M4, but then it’s 0.2s faster than the M to the metric tonne.

Like other AMGs of late, Mercedes is offering the C 63 S Coupe with a limited ‘Edition 1’ model, which for an extra $10,900 adds Selenite Grey matte paint with yellow decals, yellow-trimmed black wheels, carbon ceramic brakes, semi-slick Michelin Pilot Sport Cup 2 tyres as a no-cost option, plus subtle extra aero add-ons.

The interior of the Edition 1 is also distinguished with matte carbon trim, diamond-stitched leather seats and yellow stitching and detailing on several surfaces.

All Edition 1 features are available as individual options, but given the carbon brakes alone usually cost $9500, it’s a bit of a deal and expected to last for the first year of deliveries.

Driving

The reason why the C 63 S Coupe comes alive in third gear is that even 285mm rear rubber and the tricky diff are no match for 700Nm delivered from 1750rpm at any lesser speeds. Even at the Sport Plus end of the Comfort, Sport, Sport Plus and Race spectrum of drive modes, AMG has wisely limited the available throttle in the first two gears to preserve the rear brake pads that would otherwise be working overtime because of the stability and traction control.

Even with this controlled power delivery, the C 63 S Coupe easily breaks traction when punching the throttle at the Sydney Motorsport Park pitlane exit. This marks the start of the process of this driver weaning himself off the desire to floor it at every corner exit, with a sensitive feed of the accelerator required to keep the rear tyres in check.

We were restrained to Sport Plus during our test, but even without the loosest leash of Race Mode before turning off the stability control altogether, Sport Plus does a great job of letting you feel like you’re about to exceed your talent levels before carefully guiding you back to reality. It’s like jumping off a cliff before realising you’re attached to a bungee cord.

It’s not until after Turn 15 that a hard second-third shift is possible and the whole C 63 first and second gear furphy is revealed. It’s honestly like someone has switched on a third turbo.

The brakes start to throb as the pads approach their heat limit.

The only other point on the track where the ‘third turbo effect’ kicks in is on the main straight, and we hit our trackday host’s speed limit of 200km/h well before the Start/Finish line, or about two-thirds of the way toward Turn 1. Yes, it’s still only a momentary pleasure at a high speed circuit, but it’s a valuable glimpse of serious thrust.

There’s much more to the new coupe’s talents than a second wind of acceleration and a playful rear end though. Like the sedan and wagon, there’s a sharpness to the controls and a lightweight feel that starkly contrasts with its luxury roots.

Its squat stance results in a similar elbows-out stability on turn-in to the excellent M4, and the transmission reacts so swiftly to braking and throttle inputs that the paddle shifters are rendered little more than sweet downshift-noise generators.

After a few unrelenting laps, you can feel the grip of the front tyres waning clearly through the steering wheel, and the brakes start to throb as the pads approach their heat limit. This is a 1725kg road car after all.

Jumping across to the Edition 1 with its carbon ceramic brakes solves the braking issue, with no noticeable change in performance over several hard laps. Perhaps those yellow stickers really do hint at raceworthyness?