New Mercedes SLC 300 review

The Mercedes SLK is reborn as the SLC roadster but is its folding hard-top refinement enough to beat the Boxster and TT?

Overall Auto Express Rating

3.0 out of 5

The SLC 300 offers a strong blend of performance and economy wrapped up in a stylish exterior. The problem is that the rest of the package is feeling its age. Minor updates can’t disguise that rivals feel sharper to drive, and the ride isn’t as smooth as it should be. An Audi TT Roadster is a better all-rounder, and cheaper to buy. Perhaps surprisingly, the SLC 250d actually makes more sense.

We’ve already tried Mercedes’ new SLC (a mildly updated and rebadged SLK) with a diesel engine and in left-hand drive. While undoubtedly frugal, and set to be the most popular SLC variant, the oil-burner isn’t going to cause sleepless nights over at BMW or Porsche. So, now we’re putting the two-door roadster through its paces with, what should, be a more exciting 2.0-litre turbocharged petrol engine.

Visual updates over the old SLK aren’t huge at first glance. It’s most noticeable at the front end, where there’s a redesigned bumper and a sharper diamond grill design. Flagship AMG-Line spec brings with it a subtle bodykit, lower sports suspension and multi-spoke 18-inch alloys, too. Small changes they may be, but there’s no denying that the SLC is a pretty little roadster as a result. 

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If you owned an SLK you’ll get déjà vu stepping inside, too. Plusher materials on the dash and doors give it a more high quality feel than before, and it’s a comfortable place to sit. Yet, the layout is broadly the same as the old car, and as a result it feels decidedly dated next to the Audi TT’s slick cockpit. Details like the fiddly numeric keypad on the dash look very last generation next to a C-Class Coupe, for example, while the central screen feels old-tech.

Practicality isn’t great, either – instead of proper door bins you get silly stretchy pockets, while the boot drops by over 100 litres when the folding metal roof is stowed. That roof will now fold on the move at least, as long as you remember to start the process before you move off, but it isn’t particularly quick to do so. 

Bigger changes are found under the bonnet. The SLC’s petrol range has embraced downsizing entirely – the massive V8 in the old AMG variant is now a twin-turbo V6, for example. Here, the SLC 300 model effectively replaces the old 3.5-litre V6 of the SLK 350, instead using a 2.0-litre turbocharged four-pot offering similar performance but better economy. It’s 60bhp down on the old SLK, but has the same torque figure and is lighter. That, combined with Merc’s slickest new nine-speed autobox, means the SLC completes the 0-62mph sprint just two-tenths slower than before in 5.8 seconds.    

It’s a punchy and flexible engine, revving keenly until it tails off near the redline, and the rapid fire gearchanges help you make the most of the strong mid-range, whether you take control via the wheel-mounted paddles or leave it to its own devices. 

Our car had the optional sports exhaust system, which emits a slightly uninspiring drone at low revs but gets more vocal when you rev it. It’s nowhere near as tuneful as the old V6 though, despite sounding good for a four-cylinder. It’s also impressively economical: a claimed combined figure of 47.1mpg is better than any Z4 and on a par with the slower 1.8-litre Audi TT. That should be enough to draw quite a few buyers away from the diesel.

Unfortunately, the rest of the driving experience doesn’t quite live up to the promise. Mercedes has retuned the springs and dampers to improve body control and ride quality, but you wouldn’t know it. Mid corner bumps jolt and crash through the frame, which unsettles the otherwise composed ride, especially around town.

That’s a shame, because grip levels are strong, while the SLC feels agile in any of its five Driver Select modes. Select Sport, or the almost too firm Sport +,  and the steering weights up, the air suspension tenses and the gearbox is quicker to react. However, the steering feels numb, too light and vague so dilutes the cars sporty feel.

Also, at nearly £40k before options, the SLC isn’t all that cheap, especially considering a Porsche 718 Boxster or Audi TT S Roadster can be had for a fraction more. It’s well-equipped and solidly built, but it just can’t compete with those two in terms of driver appeal.

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