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This study investigated dual-fuel operation with a light duty Diesel engine over a wide engine load range. Ethanol was hereby injected into the intake duct, while Diesel was injected directly into the cylinder. At low loads, high ethanol shares are critical in terms of combustion stability and emissions of unburnt hydrocarbons. As the load increases, the rates of heat release become problematic with regard to noise and mechanical stress. At higher loads, an advanced injection of Diesel was found to be beneficial in terms of combustion noise and emissions. For all tests, engine-out NOx emissions were kept within the EU-6.1 limit.

For gasoline engines controlled autoignition provides the vision of enabling the fuel consumption benefit of stratified lean combustion systems without the drawback of additional NOx aftertreatment. In this study the potential of certain biofuels on this combustion system was assessed by single-cylinder engine investigations using the exhaust strategy "combustion chamber recirculation" (CCR). For the engine testing sweeps in the internal EGR rate with different injection strategies as well as load sweeps were performed. Of particular interest was to reveal fuel differences in the achievable maximal load as well as in the NOx emission behavior. Additionally, experiments with a shock tube and a rapid compression machine were conducted in order to determine the ignition delay times of the tested biofuels concerning controlled autoignition-relevant conditions.

Both, the continuous strengthening of the exhaust emission legislation and the striving for a substantial reduction of carbon dioxide output in the traffic sector depict substantial requirements for the development of future diesel engines. These engines will comprise not only the mandatory diesel oxidation catalyst (DOC) and particulate filter DPF but a NOx aftertreatment system as well - at least for heavier vehicles. The oxidation catalysts as well as currently available NOx aftertreatment technologies, i.e., LNT and SCR, rely on sufficient exhaust gas temperatures to achieve a proper conversion. This is getting more and more critical due to the fact that today's and future measures for CO₂ reduction will result in further decrease of engine-out temperatures. Additionally this development has to be considered in the light of further engine electrification and hybridization scenarios.

The influence of oil related emissions became more important in the past due to reduced engine-out emissions of combustion engines. Additionally the efficiency of exhaust gas after treatment components is influenced by oil derived components. A balancing of relevant engine oil components (Ca, Mg, Zn, P, S, Mo, B, Fe, Al, Cu) is presented in this paper. The oil components deposited in the combustion chamber, in the exhaust system as well as in the aftertreatment devices were determined and quantified. Therefore a completely cleaned DI Diesel engine with oxidation catalyst, Diesel particulate filter (DPF) and NOx adsorber catalyst (LNT) was operated in different operating conditions for 500 h in a development test cell. The operation included lean/rich cycling for NOx trap regeneration. After finishing the 500 h test procedure the engine was completely disassembled and all deposits were analyzed.