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Friction losses as well as lube oil consumption at the piston group are key factors for future engine downsizing concepts regarding to emissions and consumption. This means an early identification of friction losses and wear is essential within development. The main problem is that the wear assessment is based on long durability tests which are typically performed in a later phase. This may lead to the fact that an early optimized configuration with respect to friction can cause a potential wear problem later in the durability test program. Still ongoing trends in combustion engine engineering lead to both the minimized oil supply in the tribocontact piston bore interface and improved wear resistance. One is forced to the conclusion that understanding and quantifying wear will be a key driver for the future engine development process. The aim is a holistic concept that combines different methods to investigate wear and furthermore its combination with friction loss studies.

The AVL Load Matrix is a systematic approach to optimize durability and reliability test programs. It is based on component-specific test acceleration factors and uses damage models as well as statistics. Using the Load Matrix approach helps to achieve complete test programs while avoiding unrealistic over-testing. The paper describes the Load Matrix concept and structure as well as the process of setting up the Load Matrix for a system or component. Examples are provided on damage models, and the procedure to estimate the acceleration factors is discussed.

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.