The new Mercedes E-Class will be the first model to use the company’s OM 654 diesel unit, the first member of a new engine family.
This is going to be the brand’s first all-aluminum four-cylinder diesel engine and will equip the E220d model, replacing the old 2.2-litre unit with a new 191hp 2.0-litre which offers around 13 per cent lower fuel consumption and CO2 emissions. This translates into a combined 3.9lt/100km (72.4mpg UK) fuel economy.
The new unit is significantly lighter than the engine it replaces and more compact, weighing 168.4kg versus the old’s 202.8kg. In addition, Mercedes says that they have designed this new diesel engine to meet the RDE (Real Driving Emissions) future emissions legislation, with all relevant components for emissions reduction installed directly on the engine.
The diesel unit incorporates further insulation measures and improved catalyst coatings which take away the need for engine temperature management during cold starts or at low load. This also helps in fuel saving, especially on short trips.
The OM 654 engine is also equipped with multiway exhaust gas re-circulation (EGR) which combines the cooled high-pressure and low-pressure EGR, further reducing the untreated emissions across the entire engine map.
The E200d model is expected to use a less-powerful version of the 191hp engine with only the E220d and E350d models available at launch.
“The new premium diesels are more efficient and powerful, lighter and more compact - and they are designed to meet all future global emissions standards,” says Prof. Dr. Thomas Weber, member of the Daimler Board of Management with responsibility for Group Research and Head of Mercedes-Benz Cars Development. “In our opinion, the diesel engine is indispensable in trucks and cars if we want to further reduce the CO2 emissions from traffic.”