All car news

Is it possible to build a mass-produced sports cabriolet without all the normal drop-top compromises?

Choosing between the C63 and C63 s is simple. Because even though the S costs £6910 more, the 4-litre twin turbo V8 is recalibrated to produce 503bhp (34bhp more than the non-s), you also get an electronically controlled limited-slip differential, active engine mounts and a Race transmission mode. And choosing which body style to go for is simple: it’s the coupe, surely? The saloon and estate have a less sophisticated multilink rear axle than the coupe and the new Cabriolet, and because the Cabriolet doesn’t have a fixed roof, it will be a heavy, wobbly mess by comparison. Won’t it?

Well, the Cabriolet is indeed heavier. The drop-top C63 s, despite not having a complicated and heavy metal folding roof, is still a whopping 1925kg – 200kg more than the coupe. however, that extra heft has only dulled the performance slightly. The C63 s Cabriolet is only 0.2sec slower to 62mph than the coupe, with a time of 4.1sec. its top speed isn’t far off the coupe’s either – both are limited to the obligatory 155mph unless you specify the AMG Driver’s Package, then the Cabriolet is limited to 174mph, just 6mph shy of the coupe’s top speed. From the driver’s seat, the Cabriolet’s performance deficit is imperceptible, the big V8’S 516lb ft from as low as 1750rpm making triple-figure speeds incredibly easy to reach.

Sadly, the extra bracing that makes up the bulk of the added weight hasn’t compensated for the lack of a roof. You can feel the steering wheel move laterally in your hands, and if you select the firmer damper setting, the motion is exaggerated.

When the roof is up, there’s also the odd squeak and rattle where it meets the windscreen. in lesser C-class drop-tops with smaller engines, such as the C43 and C220,the body copes much better and doesn’t exhibit the C63’s structural shortfalls.

The Cabriolet’s lack of a roof does, however, allow you better access to the thunder emitted from the C63’S four exhausts. At start-up and idle the sound is a deep waffling noise, typical V8, but as the revs rise it transforms into something more akin to a .50-calibre machine gun. it’s brash, and with the exhaust in its loudest setting, borderline offensive, but it’s still hugely entertaining. the gearbox is the same seven speed unit in all V8 AMGS except the AMG GT. it’s not a dual-clutch ’box, but it’s almost as quick and as crisp as one. the only gripe is that if you wait until the red line to change gear, the shift is slow and stunts your progress. You have to change when the lights on the dash prompt you to, but that robs you of the satisfaction of revving the engine out. The Cabriolet might not have the rigidity of the coupe, but it does have the same lairy low-speed character. With enough throttles, it will light up its rear tyres out of slow corners and the combination of a tightly wound e-diff and quick steering means the resulting slide is effortless. The coupe’s greatest skill is that its limits remain approachable even at much higher speeds. The supremely controlled chassis works in perfect harmony with the predictable rear axle and torquey engine so you have complete confidence up to and around its limits of grip. Sadly, the drop-top just isn’t as dependable.

it doesn’t instill you with the same confidence because the lack of rigidity means you can’t feel what’s going on at tarmac level in as much detail. From turn-in to exit, it has a less aggressive attitude and doesn’t respond to your inputs with the same immediacy. You can’t tighten your line with the throttle in quicker corners, not that there’s under steer to combat, and it isn’t as satisfying as the way you can control the rear Tyres with the throttle in the coupe. The coupe, then, is still the pick of the C63 range, but the Cabriolet is almost as much fun thanks to its colossal engine and wonderfully progressive rear end.

Will Beaumont