Nearly new buying guide: Mercedes-Benz C-Class (W205)

That means the approved used dealer network is packed full of second-hand examples that will not be superseded for the better part of two years. Choose wisely and you could be driving a C-Class that, to most onlookers, will appear to be a new car, but at better than half price. 

The W205 represented a significant step forward for Mercedes’ small saloon car, not least because the extensive use of aluminium in the body structure lowered the car’s overall weight by up to 100kg compared with the version that came before it. When we first reviewed the car, in 2014, we awarded it a strong, four-star rating, praising its very slick and modern cabin, its four-fifths-of-an-S-Class styling and its mature blend of ride and handling. We had reservations about the diesel engines, which were quiet enough at a cruise but loud, clattery and unrefined under acceleration. 

Nonetheless, with much better fuel economy than the equivalent four-cylinder petrol engines and muscular torque delivery, the diesel models are the ones to look out for. The entry-level C200d diesel starts at around £14,000, but the version we’re drawn to most is the C250 BlueTec. Also a four-cylinder diesel, the C250 is much more powerful than the C200d, with 201bhp and a bulging 369lb ft of torque. Mercedes quotes a 0-62mph time of 6.6sec – brisk by any measure – and a combined fuel economy figure of 64.2mpg. 

So the C250 BlueTec is quick, frugal and good to drive. Even the entry-level SE model is reasonably well equipped, with leather trim, a reversing camera, DAB radio, cruise control and mobile phone connectivity all standard fit. The cars – and there are plenty of them – you’ll find for sale through Mercedes’ official channels will most likely be in Sport specification, which also has sat-nav, heated seats and LED lights. Range-topping AMG Line trim further adds 18in wheels, AMG bodystyling, sports seats, gearshift paddles and sports suspension. 

From new, a C250 BlueTec Sport would have cost in excess of £36,000 before options, but today you’ll find the exact same car with no more than 30,000 miles on the clock for less than £17,000. These cars have ridden the steepest part of the depreciation curve already and will now lose value at a more gradual rate. What’s more, every Mercedes Approved Used car comes with a one-year, unlimited-mileage warranty and free roadside assistance for the same term. 

When the fifth-generation C-Class appears sometime next year, it’ll arrive with yet more modern styling, a futuristic cabin and a range of ever more efficient powertrains. Until that day, however, a used W205 C-Class is both right up to date and terrific value. 

BUYER BEWARE
Engine Some 1.6 and 2.0-litre petrol models have experienced premature thermostat failure, so keep an eye on the temperature gauge. It's a difficult job to replace, so expect a large bill. Can you smell petrol? Loose or porous fuel lines have been reported on a number of cars. It's around £150 to fix. The 220d diesel engine has simplex chain tensioner issues, while the plastic inlet manifold can crack and the plastic fuel filter housing can leak.

Electrics Some reported issues with the central locking system.

Suspension, tyres and brakes Early models reported to be heavy on brakes and tyres.

Interior Sunroofs and door seals are known to creak loudly and the Comand infotainment system can freeze up. Make sure you get the latest map software as part of the deal. Where fitted, check the MB-Tex upholstery for discolouration and staining. Soon after launch, the front seats were updated to comfort seats, so is if it's an early car, check they're comfortable. 

Need to know

Although Mercedes claims a very impressive-looking 64.2mpg on the combined cycle for the C250 BlueTec, reports from owners suggest the real-world figure is more likely to be around 47mpg, with the low 50s on a longer run. 

The W205 isn’t without its reliability faults, although if you buy through the Mercedes Approved Used network, you’ll be covered by a 12-month warranty. 

A number of recalls have been issued, mostly relating to steering and airbag systems. An approved used car should have had these faults rectified, but ask the dealer to run through the relevant recalls and show proof of work.

Our pick

C250 Bluetec: Faster than lower-powered diesels but cheaper than the C300 diesel hybrid, the mid-range C250 BlueTec is the model to have. Not as plentiful as the C200d or C220d, but you won’t be short of cars to choose from.

Wild card

C350e: A petrol-electric plug-in hybrid with a combined power output of 275bhp, the C350e is a compelling alternative to the C250. However, it only makes fiscal sense for shorter journeys and city driving, and only if you can charge it on a frequent basis. 

Ones we found

• C250 BlueTec AMG Line, 2015, 50,600 miles, £17,779 
• C250 BlueTec Sport, 2015, 23,300 miles, £16,990 
• C200d SE, 2016, 34,200 miles, £13,890 
• C200 SE, 2016, 39,500 miles, £13,890