What's it like?
Let’s start with the biggest change: the new engine. It’s a fine thing. Okay, you don’t get the honeyed woofle of the old V8, but the higher-pitched, raspy howl at full chat is nice, as are the pops and bangs on the downshift, especially with the roof down. It’s not always music to your ears, mind, because a constant drone on part-throttle can get on your nerves.
We’ve no complaints about its power delivery or pace, though. Step on it and there’s just a touch of lag as the turbos puff up, after which the rev counter romps around to the redline and the SLC 43 delivers a fine turn of speed.
As it does so, the automatic gearbox manages to maintain composure and slip seamlessly through its gears, but it’s more hit and miss in manual mode. Most of the time when you pull the right-hand paddle, bang, it fires you cleanly up a gear. Then, just as you're telling your passenger, "Not even a DSG would do it better than this", it slurs into the next gear and makes you look a fool.
AMG has a pedigree of sorting chassis and it hasn't blotted the copybook here. The SLC 43 is firmer than less powerful versions but has vastly better body control. This is good news. Not only is the handling immeasurably improved thanks to less body roll, but without the standard car's rear axle hop, it rides better, too. The steering is another improvement. It feels lighter and has a more progressive build-up of weight as you pile on lock.
The problem here isn’t the settings, though: it’s the foundations. The SLC is a comparatively old car now – and it feels it. You don’t need some fancy machine to work out that it’s less rigid than a Boxster. The shimmy through the steering wheel and the little squeaks from the roof tell you all you need to know. Because of this shortfall in rigidity, no amount of AMG's fettling can deliver the degree of handling precision that you’ll get from the Boxster.
Should I buy one?
More often than not, AMG translates to 'OMG, we love it!' Sadly, not this time. The SLC 43 is okay and it can even be quite fun at times; it is a quick, rear-wheel-drive drop-top, after all. But in a class that includes the 718 Boxster, ‘okay’ isn’t anywhere near good enough.
The final nail in its coffin is cost. Yes, it is plenty cheaper than the old SLK 55, but it’s still £4600 more expensive than a standard manual-equipped 718 Boxster and barely any quicker. No matter how you try to square it, that’s hard to justify.
So it turns out the problem here isn't that a downsized engine has changed the SLC too much. It's that by morphing from SLK to SLC, it hasn't changed enough.
Mercedes-AMG SLC 43
Location Hampshire; On sale Now; Price £46,360; Engine V6, 2969cc, twin-turbo, petrol; Power 362bhp at 5500-6000rpm; Torque 384lb ft at 2000-4200rpm; Gearbox 9-spd automatic; Kerb weight 1595kg; 0-62mph 4.7sec; Top speed 155mph; Economy 36.2mpg (combined); CO2/tax band 178g/km, 32%