Parkers overall rating: 4.1 out of 5 4.1

Miles per pound (mpp) Miles per pound (mpp)

Petrol engines 4.4 - 7.6 mpp
Diesel engines 6.9 - 10.3 mpp
Plug-in hybrid petrol engines 25.6 - 32.4 mpp
Plug-in hybrid diesel engines 29.7 - 39.5 mpp
Low figures relate to the least economical version; high to the most economical. Based on WLTP combined fuel economy for versions of this car made since September 2017 only, and typical current fuel or electricity costs.
Based on "Weighted" mpg; figures depend on the proportion of miles driven in pure electric mode and may vary widely

Fuel economy

Petrol engines 25.5 - 44.1 mpg
Diesel engines 40.9 - 61.4 mpg
Plug-in hybrid petrol engines 148.7 - 188.3 mpg
Plug-in hybrid diesel engines 176.6 - 235.4 mpg
  • Range of frugal new engines impress
  • Economy figures are appealing
  • Insurance and servicing could be costly

For the highest fuel economy figures, it's inevitable that the EQ hybrid models grab the headlines. 188mpg for the petrol, and 225mpg for the diesel, is very hard to ignore. Those are weighted, of course, by the over 30-mile pure electric range; in the real world the high power diesel and petrol engines return 49mpg and 40mpg (highest claimed) and when you've used up the electric range, the C 300 e and C 300 de won't be far behind.

For the real world and long distances, the diesel C-Classes will be of most interest, with some impressive claimed mpg numbers for all. The most fuel-efficient was the C 200 d, returning up to a claimed average of 65.7mpg (NEDC).

The 194hp C 220 d returns a claimed average of 55.4mpg for the rear-wheel drive model. Find a used or nearly-new 4Matic all-wheel drive version will push that down. The 4Matic's claimed 57.7mpg is an NEDC figure - the regular C 220 d returned 61.4 under the same tests.

The petrol models can’t match even the least frugal diesel’s claimed economy figures. The most efficient petrol is the C 200, which returns up to 44.1mpg thanks in part to the EQ-boost mild-hybrid tech. The C 180 manual isn't far behind at 43.5mpg, but you'll have to work it much harder.

The more powerful C 300 claims 40.4mpg, while the Mercedes-AMG C 43 returns a creditable 29.4mpg (WLTP) despite the large twin-turbo V6 and standard all-wheel-drive. Go for the Mercedes-AMG C 63 S and you won't be surprised by its 25mpg appetite.

Day-to-day running costs for most C-Class models are reasonable, and routine servicing and maintenance is fair if you opt for a service plan. Insurance prices could also be a little higher than you might expect, especially compared with something like a Volkswagen Passat.

Green credentials

When it comes to CO2 emissions, the C-Class range varies greatly across the board. Unsurprisingly, it’s the hybrids that offer the lowest emissions figures, but the amount emitted by each model varies depending on the size of the wheels.

Clean, and green, the C 300 e and C 300 de produce 32g/km and 33g/km respectively. Combined with an electric range over 30 miles, they qualify for usefully lower BIK rates.

The C 200 d offers the most attractive CO2 emissions figure of between 108- and 118g/km, with the C 220 d claims between 117- and 126g/km of CO2. Add 4Matic to this model and you can expect between 131- and 144g/km.

Mercedes-Benz C-Class emissions

The C 200 is the cleanest of the petrol line-up, with emissions between 136- and 144g/km, with the 4Matic version returning 148-156g/km. The C 300 emits between 148- and 158g/km, while the Mercedes-AMG C 43 emits 213g/km.

Reliability

  • C-Class looks and feels solidly put together
  • Lots of recalls issued for the car, though
  • If buying used, any problems will have been sorted

The C-Class looks and feels a solidly built car, but that doesn’t mean it’s immune to problems. Issues with the AdBlue emissions system are well documented, with several revisions of NOx sensor, and as a used buy the appeal of an extended warranty is undeniable. Fortunately, for the four-cylinder models it's also very affordable.

Our own long-term C 250 d Cabriolet highlights the peace of mind offered by the Mercedes warranty, as well as the frustration of a faulty AdBlue system.

So far the Mercedes C-Class (W205) has been the subject of a number of official recalls, involving:

  • 2 x seat belt
  • 1 x axle mounting breaking
  • 1 x faulty wiring in steering assembly
  • 1 x power steering
  • 1 x flammable vapour may ignite
  • 3 x fuel leak
  • 1 x airbag

Ongoing running costs

Road tax (12 months) £0 - £475
See tax rates for all versions
Insurance group 23 - 49
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