Mercedes-AMG dials up new C 63 S Coupe

When you’re on a good thing, make it even faster.

That, in essence, is the answer from Mercedes-AMG chairman Tobias Moers or any one from Benz’s hot tuner when asked why they chose to develop the speed of the new C 63 S Coupe beyond its already impressive sedan compatriot.

On sale from March in Australia, the two-door shares its potent 375kW/700Nm 4.0-litre biturbo V8 engine, MCT 7 Speedshift automatic transmission and rear-wheel drive layout with the C 63 S sedan, all of which we have reported previously.

But there are important differences too. The biggest individual investment item in the whole program was a redesign and widening by 25mm each side of the five-link rear axle used by the sedan and the mainstream C-Class four-door and two-door models.

It is an extensive piece of work. The control arms are lengthened, the geometry reorganised and rubber bushings are replaced with metal uniball joints. The inevitable rise in road noise has been reduced or eliminated by the use of large bushings on the subframe and new damping materials in the rear diff housing.

The axle is stiffer and allows bigger 20-inch, 285mm tyres to be fitted, which makes for better traction and faster lap times. AMG sources confirm it is quicker than the sedan around the Nurburgring Nordschleife by a matter of seconds.

A shorter diff ratio also means the coupe is 0.1 sec faster through the 0-100km/h sprint than the sedan, setting a claimed best of 3.9 sec.

With punched out rear guards giving it a wide-body look, the C 63 S presents a heap tougher than the standard coupe. Front fenders are also flared to accommodate the four-link front-end that was modified from the standard W205 C-Class for the C 63 and then carried over into the coupe.

Only the roof, doors and bootlid are shared with the standard coupe. The bonnet, with its signature twin power domes, is shared with the C 63 S sedan.

“Why go beyond the sedan?” asked Moers rhetorically at last week’s international media launch in Spain. “The coupe of the previous model was well received in all markets and we had some good ideas for driving dynamics.

“The rear axle provides more traction, it provides more stability, even if you leave the throttle in cornering you have a high level of stability with that rear axle.

“And you know it changes the overall behaviour of the car. When we introduce that rear axle in our prototypes we decreased the diameter of our roll bar for example, which gives us another portion of traction.”

These improvements leave the AMG boss suspecting the new coupe may catch and pass the sedan as the most popular version of the C-Class.

“The C 63 family is a very important part of our business regarding numbers and is well received by the customers in the markets.

“It is a very important pillar in our portfolio. And there was reason to decide to have more differentiation between sedan and coupe.

“The coupe and the sedan in the past were on the same level in terms of numbers and our expectation is they will be on the same level. But the coupe will overtake the sedan in the future.”

One area where the sedan does better than the coupe is kerb weight. According to DIN figures the two-door weighs in at 1725kg, whereas the sedan is 1655kg. Both of them are porkers compared to the BMW M4, which is sub-1600kg.

“The priority was to have a nice car and a fast car on the race track, even maybe with that weight it is fast as well,” said Moers. “The thing is we invest in a car like that, the move to a dedicated body in white, the engineering of a new rear axle, there was not enough space for everything, for aluminium to be honest.”

Steel doors and rear quarter panels don’t help the cause, nor does the big V8, but the root cause of the issue is most likely to be integral stiffening built-in because the coupe has been developed in parallel with the new C-Class Cabriolet that debuts in 2016.

“The coupe is a little heaver than the sedan … and it’s hard to eliminate that,” says Moers. “We can’t modify that.”

Modification of pricing for the new coupe is also apparently proving a hard fight between Germany and Mercedes-Benz Australia-Pacific. In its final year the old 507 Edition of the 6.2-litre C 63 Coupe was priced at $159,110. And the locals want to stick somewhere in that region.

Considering the C 63 S sedan is set at $154,510 and BMW dropped the M4 price recently to $149,900, there is an argument in favour of holding the line and not gouging.

There’s also the fact that Australia is easily AMG’s best global market when it comes to share of Benz’s total sales. It sits at 13 per cent, which should translate to close to 4000 sales this year, putting AMG toe-to-toe with Porsche, something it doesn’t do anywhere else in the world.

“No other market is in double figures (for share),” said Mercedes-Benz Australia/Pacific Senior Manager of Public Relations, Product and Corporate Communications, David McCarthy. “It gives us a better bargaining position for what we want.”

Like the sedan and estate in Australia, the C 63 S Coupe will not be accompanied by the slightly less powerful 350kW standard C 63, although the priced-up Edition 1 will mark the model launch as per usual for AMG.

The S will come highly specified. So expect — among much more — AMG Ride Control sports suspension with electronically controlled shock absorbers, an electronic rear locking differential and AMG Dynamic Select drive programs, dynamic engine mounts, performance exhaust, COMAND online controller system, head-up display, LED headlights, Nappa leather, a panoramic sunroof and metallic paint.

Look out for our first drive of the new C63 S Coupe tomorrow (November 10).