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The need for significant reduction of fuel consumption and CO₂ emissions has become the major driver for development of new vehicle powertrains today. For the medium term, the majority of new vehicles will retain an internal combustion engine (ICE) in some form. The ICE may be the sole prime mover, part of a hybrid powertrain or even a range extender; in every case potential still exists for improvement in mechanical efficiency of the engine itself, through reduction of friction and of parasitic losses for auxiliary components. A comprehensive approach to mechanical efficiency starts with an analysis of the main contributions to engine friction, based on a measurement database of a wide range of production engines. Thus the areas with the highest potential for improvement are identified. For each area, different measures for friction reduction may be applicable with differing benefits.

Significant weight reduction on the powertrain can only be achieved by the combined use of lightweight materials with specific design approaches. The component with the highest contribution to the engine weight is the crankcase. As the central component with many integrated functions, new crankcase concepts require comprehensive development in view of the mechanical and acoustic behavior. After basic concept development and FE-analysis a test engine was built to evaluate the forward-looking light-weight concepts under realistic conditions. Especially the comparison of modern cylinder running surfaces was a topic of extensive material investigation and engine durability tests. Both Aluminum and Magnesium were investigated as material for the crankcase of the test engine. Beside the functional aspects the production cost of lightweight concepts is the decisive issue for their implementation in volume production.