2017 Mercedes-AMG C63 S & C43 Cabriolet Review

What makes a real AMG convertible? We put the two new C-Class contenders to the test.

The upcoming Mercedes-AMG C63 S and Mercedes-AMG C43 Cabriolets are competing for the hearts and minds of those few that can justify their expense in line with their amazing characteristics and flaws.

When it comes to convertible sports cars, there is really no mediocrity - they are either great or not so great, with an extremely fine line in the middle between them.

Unlike sporty coupes, the convertible world is riddled with the additional compromise of a moving roof, which reduces the body rigidity, which in turn is subsequently strengthened with underbody work that adds more weight and complexities. The result is generally a car that feels its weight significantly more than the coupe that it is based on.

It’s as if there is a tipping point though, whereby the ratio between weight and power becomes too much, where the car is either still cohesive in its handling ability with enough power to make it fun, or it goes past the point of no return and becomes too heavy to perform as it was intended.

Here then, between the Mercedes-AMG C63 S and C43, we have one of each, and the good one is probably not the one you think.

Having driven the Mercedes-Benz C300 Cabriolet extensively, we can say without a shadow of a doubt it’s the sweet spot in the entire range in terms of getting the best out of the intended purpose that is this four-seater Mercedes cruiser.

Nonetheless, if AMG is your game, then the C43 4MATIC (all wheel drive) presents – at first glance – an interesting proposition. Powered by a 3.0-litre six-cylinder engine, the first C43 offers up 270kW of power and 520Nm of torque, which when combined with a nine-speed automatic transmission will catapult the entry model AMG convertible from 0-100km/h in 4.8 seconds.

But that’s where the fun seems to stop because, for as far as we could tell, the C43 lacks the driving characteristics we’ve come to love and expect from engineers at AMG.

Firstly, it’s all-wheel drive, which is a safe option and a great way to get the power down in slippery conditions, but that in turn means it misses out on the hooligan characteristics of what a C-Class AMG has always been.

Furthermore, the additional weight of the AWD system, in combination with the roof (which adds 135 kilograms over the coupe), tips the C43 Cabriolet to 1795kg (kerb), just 55kg shy of the rear-wheel drive C63 S Cabriolet, which has significantly more power from its 4.0-litre twin-turbo V8 (with a 0-100km/h time of just 4.1 seconds).

That results in the C43 feeling a little underwhelming around bends, with a very nose-heavy feel to the car in the twisty stuff. Also, the engine itself needs the optional sports exhaust system to make it sound good, otherwise it’s rather muted and unlike any AMG-badged model we’ve heard before.

In complete contrast though, and to show how much difference just 135kg can make, we also drove the C43 Coupe and found that to be an absolute cracker of a thing. Super nimble into corners with a thirst for more. Almost chalk and cheese between it and its convertible sibling. Of course, Mercedes-AMG has also modified the suspension on the cabrio to make it more of a ‘cruiser’ than anything else, and that certainly shows. In that regard then, stick with the C300 Cabriolet if you can’t stretch to the C63 S - you wont regret it.

Moving on to the C63 S AMG Cabriolet, it’s hard not to get excited. Our car came in a gorgeous Selenite Grey combined with a red roof and beautiful retro rims that made it look like something between a classic convertible and modern muscle car. It’s arguably the best looking convertible in its class.

Power up the monstrous 375kW and 700Nm V8 and instantly there is a rumble that makes you realise the difference between this, a real AMG, and the C43. In saying that, this is also very much a cruiser, though its additional power and rear-wheel drive setup makes its driving characteristic far more exciting than it probably has a right to be.

On the damp roads of Slovenia, we found ourselves giggling with delight everytime the rear stepped out in another attempt at murder. This is what an AMG is meant to be: fun to drive fast and demanding of respect at all times.

On the open road the front end of the C63 felt much easier to push hard into corners than the C43’s, no doubt due to not having to deal with an AWD system. That results in the sort of sporty convertible you actually want to drive fast, not having to worry too much about its compromises.

For us then, if you're after a C-Class Cabriolet with an AMG badge, go for the C63 S, if you can't afford that, go back to the C300 which already comes with the AMG body kit and you won't miss all that much.

Like the rest of the C-Class Cabriolet range, the AMG models have an automatic roof that operates in 20 seconds at speeds up to 50km/h, which is almost the best in class if you discount the ageing A5 convertible (which is about five seconds quicker).

For a more detailed look at the ins and outs of the C-Class Cabriolet and its functionality as a convertible, read our general review here.

For us, the C63 variant deserves an 8.5/10 while the C43 is a 7.5.