What is it?
The Mercedes-AMG S 63 AMG represents the middle ground to Mercedes-Benz’s newly re-established S-Class Cabriolet line-up – the first from the German car maker since the iconic W111 series model back in 1971.
Positioned between the S 500 Cabriolet and the even more exclusive S 65 Cabriolet, the plush four-seater is due to hit UK showrooms next month wearing a price tag of £135,675. This pitches it £50,000 below its closest perceived open-top rival, the Bentley Continental GT Convertible Speed, which goes for £185,200.
Predictably, the S-Class Cabriolet adheres closely to the latest S-Class Coupé. The two share the same basic design, mechanical package and luxurious leather-lined four-seat interior, which can be enhanced by a seemingly limitless amount of optional features.
To accommodate what is claimed to be the largest fabric roof applied to a current production car, the new open-top adopts a unique windscreen with greater rake and a more substantial frame for added rollover protection.
It also receives a uniquely designed rear end with added stiffening within the rear bulkhead, rollover structures designed to deploy from behind the rear seats, a tonneau cover that opens to reveal a large storage compartment for the roof and longer bootlid.
With a claimed drag coefficient of 0.29, Mercedes says the S-Class Cabriolet is the most aerodynamically efficient car in its class. It has also developed a new sealing process for the doors and provided its latest model with double-glazed side windows in efforts to match the competition for outright refinement.
As with the latest S 63 Coupé launched in the UK last year, the S 63 Cabriolet runs AMG’s twin-turbocharged 5.5-litre V8 petrol engine. The 90deg unit produces 577bhp, giving it 129bhp more than the twin-turbocharged 4.7-litre V8 in the S 500 Cabriolet but 44bhp less than the recently upgraded twin-turbocharged 6.0-litre V12 found in the S 65 Cabriolet.
Power is delivered to all four wheels via AMG’s seven-speed automatic Speedshift gearbox and a 4Matic four-wheel drive system engineered to provide a nominal 33/67 front-to-rear torque split. There are three driving modes to choose from: Controlled Efficiency, Sport and Manual.
The S 63 Cabriolet is underpinned by a uniquely tuned version of Mercedes-Benz’s air sprung Airmatic suspension with adaptive damping, offering the choice between Comfort and Sport modes. AMG has focused quite a bit of attention on the underpinnings, providing the front wheels with added camber and adopting a larger-diameter roll bar than that of the standard S 500 Cabriolet up front. The rear also receives a stiffer subframe.
The ride height can be raised by 30mm at the press of a button. The chassis then lowers again automatically when switched to Sport mode at speeds of more than 75mph.
What's it like?
Driving the Mercedes-AMG S 63 Cabriolet is an event, whether you’re running with hood down along a sun-drenched boulevard on the French Riviera or pushing it to the limit on a lonely back road on one of the mountain passes used for the Monte Carlo Rally. For sheer opulence and sense of occasion it is right up there with the Bentley Continental GT Speed Convertible.
In terms of outright performance and overall dynamic ability, though, it goes one better than its most closely matched high-end soft top rival, delivering a truly heady combination of pace and handling prowess – the likes of which I suspect few potential owners are ever likely to sample in full effect.
The sturdy reserves of the AMG-assembled engine make light work of the big open-top's 2110kg kerb weight, propelling it with effortless verve and truly muscular qualities. Huge levels of low-end shove endow it with terrific flexibility around town and consummate cruising ability out on the open road. Mechanical refinement is magnificent and the whole drive process operates with silken smoothness.
Open the taps to release the full quota of power along with a sturdy 663lb ft of torque and it also proves to be captivatingly rapid and engagingly boisterous. This Jekyll and Hyde persona is very much at the root of the appeal of the new Mercedes-AMG model, which is produced alongside other S-Class models at Mercedes-Benz’s main manufacturing site near Stuttgart in Germany.
The S 63 Cabriolet looks and sounds better with its multi-layered fabric hood folded away under a tonneau cover behind the expansive four-seat cabin. The large structure can be opened in just 20 seconds at speeds of up to 31mph.
The overall effectiveness of the S 63 Cabriolet’s V8 engine, seven-speed automatic AMG Speedshift gearbox and 4Matic four-wheel drive system is displayed in Mercedes-Benz’s claimed 0-62mph time of 3.9sec. This is 0.5sec faster than Bentley quotes for the 2495kg Continental GT Speed Convertible. The Mercedes’ top speed is capped at 155mph.
The appeal extends further than just its straight-line speed and inherent refinement, though. The big four-seater also steers with incisive directness and accuracy and its advanced air-sprung underpinnings provide it with a level of agility and body control belying its significant mass.
Granted, it is no sports car, but it can be hustled quickly along challenging back roads with a great deal of confidence. The body feels wonderfully rigid, with only the odd pang of scuttle shake spoiling its otherwise impressive deportment. Thanks to the effects of four-wheel drive, traction is never in doubt, while big brakes also ensure it stops quickly and reassuringly.
Although firmly sprung, the ride quality of the S 63 Cabriolet is impressive. Even on 255/45 front and 285/40 rear tyres it delivers excellent compliance and bump absorption. It is not quite as smooth over broken bitumen as the standard S 500 Cabriolet, but it is never unpleasant.
Should I buy one?
At £135,675, the S 63 Cabriolet could hardly be described as a bargain. However, you do get a lot of car for the money. Few cars at any price so successfully combine such urgent performance and cosseting comfort the way the big Mercedes-Benz manages.
It also feels wonderfully engineered, is impeccably built and big on perceived luxury. If you can afford it, it is a fine way to travel - roof up or roof down.
Mercedes-AMG S63 Cabriolet
Location Nice, France; On sale Now; Price £135,675; Engine V8, 5461cc, twin-turbocharged, petrol; Power 577bhp at 5500rpm; Torque 663lb ft at 2250rpm; Gearbox 7-spd automatic; Kerb weight 2110kg; 0-62mph 3.9sec; Top speed 155mph (limited); Economy 27.2mpg (combined); CO2/tax band 244g/km, 37%