There’s nothing particularly wrong with the SLC 43. But on the other hand, there’s nothing particularly outstanding about it, either. While we accept that it is not a full-blown AMG model, it disappointingly lacks the sort of dynamic qualities one expects of a car conceived to take on such exceptional machinery as the Porsche Boxster.
The big news, of course, is the arrival of a new AMG engine. The twin-turbocharged 3.0-litre V6 petrol unit, first unveiled in the C 450 4matic Sport last year, provides the 1520kg SLC 43 with an impressive turn of speed and, in Sport Plus mode, a truly stirring exhaust note. However, it lacks the outright response and high-end heroics of the naturally aspirated 5.4-litre V8 used in the discontinued SLK 55 AMG.
The outright potency of the new V6 engine is reflected in the SLC 43’s official 0-62mph time of 4.7sec. This is just 0.1sec shy of the claimed 4.6sec of the SLK 55. But while it manages to deliver similar performance to its more powerful V8 predecessor, it is nowhere near as entertaining when stirred with a heavy dose of right foot, owing to an excessive amount of induction blare and a relatively low 6000rpm redline.
What the 60deg engine does deliver, though, is exceptional low to mid-range flexibility. This, coupled with an extra two gear ratios thanks to the adoption of Mercedes-Benz’s latest nine-speed 9G-Tronic automatic gearbox, provides the SLC 43 with highly agreeable cruising qualities and highly competitive combined cycle consumption of 36.2mpg, giving the new performance orientated roadster average CO2 emissions of 178g/km.
In other areas the new Mercedes-Benz is a mixed bag. Among the positives is its overall refinement, which is excellent by roadster standards. The folding hard-top roof, which now operates on the go at speeds of up to 25mph and comes with an optional automatic boot separator, continues to impress. With a 335-litre boot capacity when the roof is up and 225-litre capacity with it down, boot space is also quite good by class standards
What lets the SLC 43 down is its lacklustre dynamic ability. On the upside, the changes brought to the SLC 43’s suspension, including unique front axle geometry, make it a more engaging car to drive than any of the other SLC models. The variable rate steering is particularly good, offering greater directness and accuracy than the standard set-up.
Predictably the ride is firm, although it is not as uncompromising as it was in the old SLK 55. Encountering a pothole when the suspension is loaded up in corners can cause the body structure to shimmy, although it quickly settles. Yet despite the obvious shortfall in rigidity, the reworked chassis delivers a good deal of grip and impressive body control, prompting you to push the new Mercedes-Benz hard when the conditions allow.
However, the SLC 43’s stability control system is a continual annoyance when you up the pace over challenging back roads. Whether in Sport or Sport Plus mode, the electronic safety net persistently begins to cycle as you charge into corners, ultimately curtailing any real driving enjoyment that might be on offer.
As a result, the range-topping SLC rarely feels rewarding in the way a small sporting roadster with an AMG badge on its boot lid perhaps should on an open road. Rather, it comes across as being disappointingly aloof and lacking in critical dynamic ability. It’s fine when you’re cruising along but doesn’t respond well when hustled hard, especially in tight corners like those we encountered during the SLC 43’s launch.