Mercedes C-class fuel tank shrunk to supermini size

A significant portion of the new Mercedes-Benz C-class's weight savings have been made possible by a tiny 41-litre fuel tank, it has been revealed.

As much as 16 per cent of the average 75kg saved by the new W205 generation of C-class over its predecessor is attributed to its small tank. Industry sources say this move is an example of how car manufacturers are using every possible engineering and legislative tweak to reduce the CO2 ratings of their new models.

By shrinking the standard-issue tank by 18 litres, Mercedes has managed to shave almost 12kg off the official kerb weight. Under EU regulations, a model’s official kerb weight is calculated using a fuel tank filled to 90 per cent of its capacity, as well as an additional 75kg for the driver.

During official NEDC fuel consumption tests, the petrol-engined C-class was filled with just 36.9 litres of fuel at the start, compared with the 53.1 litres carried by the previous-generation C-class. Although the small fuel tank allowed the benchmark C-class to be lightened by less than one per cent, it was clearly considered a worthwhile move by Mercedes.

In Germany, the new C-class is sold with an optional 66-litre fuel tank, for which Mercedes charges €59.50 (about £49). In the UK, this 66-litre tank will be fitted as standard, but official figures will be quoted from the European standard and the 41-litre tank. 

A Mercedes spokesman said: “We have reduced the fuel tank capacity of the new C-class roughly in line with the fuel savings it offers over its predecessor. For those customers who place a priority on range, we offer an optional 66-litre tank.

“The reduction in weight of the new C-class has led to a significant improvement in payload capacity. This is up by 50kg and is now 90kg higher than the competition.”

The new C-class will go on sale in the UK in June, and features an all-new cabin with technology derived from the new Mercedes-Benz S-Class, as well as a range of economical engines offering under 100g/km of CO2 emissions on some models.