The Mercedes-Benz OM 654q four-cylinder diesel from the modern OM 654 engine family already complies with the Stage 2 RDE (Real Driving Emissions) standard which does not come into force until 2020, and is certified to Euro 6d.
With its near-engine installation, the emission control system has low heat losses and thus very favorable operating conditions in the vast majority of operating situations. Further measures include:
High and low-pressure exhaust gas recirculation including cooling;
a diesel oxidation catalytic converter (DOC) to avoid the emission of carbon monoxide (CO) and unburned hydrocarbons (HC);
a particulate filter for capturing soot particles with combined SCR catalyst function (sDPF);
an SCR catalytic converter (selective catalytic reduction) for reducing nitrogen oxides. For this purpose, ammonia in the form of the carrier AdBlue is mixed in with the exhaust gases and conditioned before entering the sDPF, an additional underfloor catalyst (SCR) with ammonia slip catalyst coating (ASC).
NOx emissions demonstrator. The NOx emissions demonstrator from Mercedes-Benz Diesel Car Development shows how efficiently the emission control technology works. The vehicle corresponds 100% to the series production configuration in terms of the engine and emission control system as well as the control unit software.
The additional sensors and visualization options are intended to provide an experience of the emission performance on the road in a host of driving situations.
For illustrative purposes, here are six different journeys driven in a Mercedes-Benz A 220 d (combined fuel consumption 4.5-4.3 l/100 km; combined CO2 emissions 118-114 g/km):
Country road in the vicinity of Stuttgart
Country road with climb to the Swabian Alb
Mountain road (Feldberg Pass) with/without passengers
Mountain road (Feldberg Pass) including cool-down of the engine during descent
Stuttgart city center
Mercedes-Benz started an engine initiative in 2016, which includes the all-new four-cylinder diesel engines (OM 654 and OM 654q) as well as straight-six diesels (OM 656). On this basis, which is associated with investments of around €3 billion, a whole host of Mercedes-Benz diesel models, from the A-Class to the GLS, already comply with the Euro 6d standard.