• Range of frugal newer 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. That’s a claimed 141-188mpg for the petrol, and 176-256mpg for the diesel on the WLTP ‘real world’ Combined test. Those are weighted, of course, by the 30-miles-plus of pure electric range – in the real world the high power diesel and petrol engines return 49mpg and 40mpg respectively (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 long-distance drivers, 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 49-60mpg (WLTP).

The 194hp C 220 d returns a claimed average of 49-57mpg for the rear-wheel drive model. Finding a used 4Matic all-wheel drive version will push that down. The 4Matic’s claimed 44-52mpg shows that choosing four-wheel drive has a penalty at the pumps.

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 35-44mpg thanks in part to the EQ-boost mild-hybrid tech. The C 180 manual isn’t far behind at 36-41mpg, but you’ll have to work it much harder.

The more powerful C 300 claims 35-40mpg, while the Mercedes-AMG C 43 returns a credible 29mpg 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 more than 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.

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.