The Class C BlueEFFICIENCY are tuned variants of Class C to have a lower consumption compared to the versions of those derived.

These versions are made from Class C 180 and C 200 CDI. There is also a Class C BlueEFFICIENCY 350 CGI that does not have the engine in the current C 350, 272 hp, but a separate direct injection and 292 hp.

So far, Mercedes-Benz has not determined what day will arrive in Spain. On arrival, these versions do not replace the Class C equivalent, but will make an alternative within the range.To lower consumption in versions BlueEFFICIENCY, Mercedes-Benz slightly reduces the weight of some elements, improves aerodynamic coefficient reduces the rolling resistance and, in the 180k and 200 CDI lengthens developments transmission.

Moreover, in the 180 K BlueEFFICIENCY changes are more profound: it has an engine cylinder capacity of less that 180k currently sold-goes from 1.8 to 1.6-l, while maintaining the power 156 hp). The 350 CGI has a 292-hp V6 engine with a new injection system. Currently, this engine is only available in the CFA (technical information engine 350 CGI).
Compared with the equivalent versions of the Class C, BlueEFFICIENCY have a clear advantage in reaching the maximum speed and the consumption (comparison chart).

Compared with the cars of competition, no other saloon equivalent to Class C BlueEFFICIENCY 180 K, 220 to 350 CDI or CGI to reach over maximum speed with a power similar. Consumption of these versions is also very good, although a 180K or 200 CDI spent more than a BMW 318d and a BMW 318i, respectively (both BMW have 143 hp). The Class C 350 CGI that it spends less than any car petrol power, including the BMW 335 Aut. From 306 hp.
Depending on the variant, the weight of the versions BlueEFFICIENCY is reduced between 19 and 32 kg compared with the normal versions of Class C. Part of the weight reduction is because the windshield is of a different kind. Between the two layers of glass that make up the windscreen, there is a new plastic membrane, which has a greater capacity to absorb the noise caused by the wind. This new membrane reduces the size (and therefore the weight, around 1.2 kg) of the two layers of glass that make up the windscreen.
To reduce weight without increasing the amount of noise that comes inside, Mercedes-Benz has changed the thickness and type of foam that separates the passenger compartment space for the engine. With this solution the weight of the insulating material around a low 20%.

The wheels are forged aluminum. This type of tires reduced a total of more than 7 kg regarding tire equivalents aluminium smelter which are conventional versions. These tires also have forged a design that favors the aerodynamic resistance to the advance is less.
The tyres are also different. Mercedes-Benz has developed together with a new kind of Michelin tires that have less resistance to progress. It is given by the contact with the ground and its deformation.

To reduce distortion, the metallic structure of the tire is made of high strength steel, which also has the advantage that allows each tire is lighter (about 1.7 kg game). To reduce resistance generated by the tire contact with the ground, there are also changes in the flank and the rubber of the tread (which is directly in contact with the asphalt).
According to Mercedes-Benz, 120 km / h to 50% of the entire load having a car is provided by aerodynamics. The Class C BlueEFFICIENCY has an aerodynamic coefficient (CX) of 0.25. A conventional Class C 220 CDI has had a series of CX of 0.27 and a 180K, 0.29.

The address remains hydraulic assistance, but the models have a valve BlueEFFICIENCY additional disconnects the pump when it is not necessary (when the car wheel in a straight line).
Finally, another measure to lower consumption is that everyone is an indicator of consumer instant instrumentation.

The Mercedes-Benz C180 K has changed the cylinder capacity of 1,796 cm ³ to 1,597 cm ³. The power and the maximum torque remains unchanged despite the changes: 156 hp and 230 Nm respectively. In addition to reducing engine, there are changes to reduce the friction of moving parts and in the combustion chamber to improve the mix of air and fuel.