Used Mercedes C-Class Cabriolet 2016-2021 review

Many people desire a convertible but also occasionally need four seats and a well-sized boot, so the likes of a dainty little two-seat roadster are out of the question.

What they need is something like this Mercedes C-Class Cabriolet, a car clearly based on the solid and dependable coupé version of the same car but one that can be flung open to the elements at the touch of a button.

Underneath, the C-Class Cabriolet does indeed share the same set-up as the coupé model, which in turn has a different front suspension, a lower ride height and quicker steering than the regular C-Class saloon. The convertible model also offers the option of air suspension and, since that seems to noticeably improve ride quality, we think that’s well worth seeking out.

Engines: There are plenty of engine options, from the C200 and C300 petrols through the popular C220d and C250d and C300d diesels to the C43, C63 and C63 S high-performance AMG models. The C-Class is rear-wheel drive, although there is the option of four-wheel drive on some models and a standard feature on the super-sporting C43 and C63 S models.

Trims and equipment: There were two trim levels initially: Sport and AMG Line. Entry-level Sport includes 17in alloy wheels, LED headlights, faux-leather seats, keyless entry, climate control, heated and electrically adjustable front seats, front and rear parking sensors, a reversing camera, swish ambient lighting, a wind deflector and an Airscarf system that blows warm air into the back of your neck, keeping you warm when you have the roof down, even on a cold day. AMG Line adds sports suspension, more direct steering and mainly cosmetic changes; you get more aggressive looks, bigger wheels and a sporty makeover for the interior, too.

Later, post-2018 facelift models changed these trims to the AMG and AMG Line versions, though you could add Edition, Premium Edition and Night Edition Premium Plus packs, just to confuse the issue.

Ride and handling: On the road, the C200 and C300 petrol cars are reasonably brisk but, perhaps surprisingly, don’t feel much smoother than the diesel options. The entry-level C220d feels lively, whereas the C250d feels encouragingly quick, as does the later C300d. All of them could be a little more refined, but the combination of performance and economy is difficult to beat. The ripsnorting AMG models all have fire in their belly, from the six-cylinder C43 to the twin-turbocharged V8 C63 and later C63 S, the latter of which is exceedingly quick.

In the bends, Sport models offer delightful handling, but if anything the stiffer AMG Line cars are even better tied down and more fun. Needless to say, the AMG models are properly quick, with lots of grip as well as adjustable and pin-sharp handling. All models ride pretty well, from the softer lower-level models up to the fastest ones, although there is some thumping through the seats on poor surfaces, so it’s worth seeking out a car equipped with the optional air suspension, which adds another dimension to the ride quality.

Pleasingly, the C-Class Cabriolet feels solid in a way that few convertibles do, with little shake through the scuttle.

Interior and practicality: Inside is a truly special-looking interior, with plenty of leather. The driving position is excellent, being fully electrically adjustable. All the controls are easy to reach and the 7.0in screen, with sat-nav included, is mounted usefully high up on the dashboard. However, neither the standard infotainment nor the expensive Comand system upgrade, which offers more functions and an 8.4in screen, is as slick nor intuitive to use next to BMW’s iDrive.

Not surprisingly, perhaps, front space is excellent, but the two rear passengers will find the going a little tight. With the roof up, the boot’s a good size, although access is a little shallow; lowering the roof limits the available space.

Euro NCAP awarded the C-Class Cabriolet a full five-star safety rating when it was new and scores in each category stand up well against rivals. Automatic emergency braking and a driver attention monitor are standard across the range, while an optional safety pack adds features such as blindspot monitoring and lane-keeping assistance.

If you're interested in buying a used Mercedes C-Class Cabriolet, or any of the other cars mentioned here, check out our used car classifieds site here.

You’ll need to fork out about £12,000 for a C-Class Cabriolet. This should pick you up a 2016 model, petrol or diesel, with an average mileage for the year and a full service history. Up this to between £15,000 and £17,000 for a 2017 car with the same criteria. More than £18,000 will be needed to buy you 2018 or even 2019 cars with low mileages. Spend around £20,000 plus on 2020 and 2021 models. You’ll need around £25,000 for a C43 or C63 S model.

MPG

On paper, the C220d is the most economical. In lower-spec Sport trim, it claims an average fuel consumption figure of 62.8mpg under the older NEDC tests, with corresponding CO2 emissions of 116g/km. In AMG Line trim, consumption rises to 57.7mpg – a figure that's matched by the faster C250d. The petrols perform reasonably well, with the C200 managing a claimed 47.1mpg in Sport trim, with CO2 emissions of 136g/km. Not surprisingly, the hot AMG models struggle to get into the 30s.

Under the later and more realistic WLTP tests, the C200 averages 38.2mpg, the C220d 52.3mpg, the C300 37.2mpg, the C300d 48.7mpg, the C43 27.7mpg and the C63 S 25mpg.

Road tax

Annual tax for cars registered before April 2017 are based on CO2 emissions and can be high. Those registered after that will pay the new flat rate, at £190 a year at present, but beware: cars that cost more than £40,000 new – and that’s most of them – attract an annual luxury surcharge tax, currently £410 a year.

Insurance and servicing

Insurance is quite high, too, with groups ranging from 36 to 50, depending on power output. Servicing costs are likely to be high, too, but Mercedes does operate a number of pay-monthly plans you can opt into.

Reliability

Owners participating in our annual What Car? Reliability Survey have found the Mercedes C-Class to be mostly reliable, maintaining its dependability over several years.

However, some owners reported faults, notably with exhaust gas sensors failing, particularly in cars with less than 50,000 miles, which could lead to costly repairs.

Experiences with Mercedes' dealer network varied, with mentions of high servicing costs at brand dealerships. Costs associated with updating sat-nav maps and consumable parts were also highlighted as concerns for some owners.

Our dedicated reliability page can tell you more about the C-Class’s common problems.

We’d bypass the C200d and step up to the C250d, or even the C300d if you're buying a later car. It’s punchier, slightly quieter and nearly as economical.

Sport may be the entry-level trim on the earlier cars, but it still has plenty of kit including climate control, heated electric front seats, a reversing camera, a DAB radio, sat-nav, adjustable ambient lighting, LED headlights, a wind deflector and the Airscarf system. It’s the one we’d seek out.

Our favourite Mercedes-Benz C-Class Cabriolet C250d Sport

The Audi A5 Cabriolet is comfortable, handles well, has a beautiful interior and some quite competitive running costs. It’s not as exciting to drive as one or two of its rivals, admittedly, but its quality is outstanding and it makes a very keen used buy.

The earlier version of the BMW 4 Series Convertible is imbued with all the traditional qualities the marque is famous for. It’s well built, good to drive, has a great infotainment system and is reasonably well equipped. Against that, some of its diesels lack refinement and the manual gearboxes are a little old-fashioned. This model was replaced in 2020 by an all-new version.

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If you're interested in buying a used Mercedes C-Class Cabriolet, or any of the other cars mentioned here, check out our used car classifieds site here.