The public and governmental pressure for lowering GHG emissions from the transportation sector is continuously increasing. Since the release of the new CO2 target figures from the European Commission (EC), formulating massive reduction degrees in the next decade (-15% in 2025 and -37,5% in 2030), substantial initiatives have been engaged to ensure proper achievement and compliance with these ambitious targets. Diesel powered vehicles and, in particular, light-duty Diesel engines have been the major driver for continuous year-to-year fuel consumption reduction rates in the recent past. These achievements so far were mainly based on continuous enhancement of combustion efficiency and reduction of mechanical losses. Based on this experience, it appears unlikely to realize further substantial improvements by extension and prolongation of this technical approach, like requested by the legal authorities for the mid-term future. Double digit lowering rates request for implementation of new features and technologies. As purely electric propulsion systems gain increasing attractiveness for small light-duty applications, due to a better balanced trade-off between costs and daily operational duties, heavier light-duty vehicles, often used for commercial needs, demand different powertrain concepts, especially if heavy goods transportation, long distance driving and/or trailer towing demands are requested as well from the end-user side. In order to safeguard both, upcoming legal GHG reduction norms as well as all-day operational duties, new powertrain configurations are requested. One attractive conceptual layout is found by the mixed-serial hybrid topology, labeled Diesel EMotion. This powertrain concept features a tailored cost-optimized Diesel engine with a strong electric machine as a serial hybrid, while featuring in conjunction with a simple one-speed transmission a direct, highly efficient coupling of the engine with the drive wheels. The vehicle is mainly driven by the electrical machine, especially in urban regimes, but, as soon as vehicle speed and load exceed certain threshold values, the direct connection between engine crankshaft and driving wheels is enacted to realize best fuel efficiency. The paper in hand describes at first the conceptual layout of the advanced powertrain topology for heavy Light-Duty vehicle applications, balancing functional performance in the limited engine operational map with corresponding cost reduction measures. Furthermore, initial functional performance figures, especially in comparison to conventional powertrain definitions as well as to classical serial hybrid designs are displayed. The paper concludes with a summary and parameter ranking in order to determine next steps in realization and industrialization PREPARERD FOR: FISITA 2020 – PRAGUE/CZECH 2020 Topics • Stringent EU CO2 targets in transport sector • New propulsion system topology • Mixed-serial Diesel hybrid layout
