From the outside it looks just like a more than 20 year-old Mercedes 190, tens of thousands of well-preserved examples of which can still be seen on Germany’s roads. Pressing the accelerator tells a different story: equipped with the ultra-modern OM651 common-rail engine developing 150 kW / 204 hp, the Mercedes 190 D BlueEFFICIENCY shows the full potential of this new four-cylinder diesel engine.

C-Klasse

With a maximum torque of 500 Nm between 1600 and 1800 rpm, this experimental car has more than twice the torque of the most powerful model in the old W 201-series. The 190 E 2.5-16 Evolution II, which was presented in 1990 and produced 502 times as a homologation model for the Group A DTM touring cars, “only” manages 245 Nm.

The idea for this unusual experimental vehicle came about during an evening discussion about the enormous developments in diesel technology over the last 20 years. The question was: “How might one make this progress directly tangible, in isolation from the equally profound changes in the safety and comfort of the car as a whole?” The result was a factory-tuned car of a different kind: the 190 D BlueEFFICIENCY. It accelerates from 0 to 100 km/h in 6.2 seconds. It therefore manages this standard sprint 11.9 seconds faster than a 190 D of the time, which caused a sensation on its 1983 introduction with its newly developed, fully encapsulated “whisper-diesel”.

The differences between the two diesel generations are even more impressive when it comes to fuel consumption: despite the significant increase in output by 72 hp (OM 601, 1988) to 204 hp (OM651, 2009), the new engine in the old body consumes 4.9 litres per 100 kilometres (NEDC) instead of the 7.3 litre figure for 1988.

But what is really astonishing is that measured according to the DINstandard used during the time of the 190 D, the Euro-Mix consumption of the current C 250 CDI BlueEFFICIENCY is a mere 4.6 litres per 100 kilometres, and 5.1 litres per 100 kilometres according to the present NEDC method. This represents an improvement of around 30 percent – not to mention the exhaust emission levels.

The playing field is by no means level: a Mercedes 190 D is 385 kilograms lighter than a current C 250 CDIBlueEFFICIENCY, for example. In addition to more interior space – the current C-Class model is 16 centimetres longer, and around nine centimetres wider and higher than a 190 – this is due to the high standard of comfort and safety features.

As a genuine Mercedes, the model 190 was ahead of its time in terms of safety technology. Nonetheless, customers at the time enjoyed nothing like the extensive array of passive and active safety systems to be found as standard in the current C 250 CDIBlueEFFICIENCY. These include seven airbags, the adaptive AGILITY CONTROL suspension and numerous assistance systems such as ESP® and
ADAPTIVE BRAKE. Comfort-enhancing features like the ergonomically exemplary, multi-adjustable seats or electrically adjustable and heated exterior mirrors also contribute to the higher weight.

A number of factors are responsible for the outstanding efficiency of the current C-Class. Aerodynamics is one of them: with a Cd figure of 0.34 the 190 set an example for its time. The new C-Class betters this figure by far, however, and is once again the trendsetter in this segment with a Cd figure of 0.27. The progress is equally impressive where the powertrain is concerned: while the 190 D was equipped with a four- or optionally five speed manual transmission, the C 250 CDIhas six gears available. Plus a large number of friction-reducing measures. The radiator fan, power steering and generator also operate much more efficiently than 20 years ago.

Source: Daimler AG