Six diesel, kerosene, gasoline-like, and naphtha fuels have been tested in a single cylinder diesel engine and a demonstrator vehicle, both equipped with similar engine technology and optimized for advanced combustion performance. This study was completed in order to investigate the potential to reduce engine-out emissions while maintaining engine efficiency and noise levels through changes in both engine hardware and fuel properties. The fuels investigated in this study were selected in order to better understand the effects of ignition quality, volatility, and molecular composition on engine-out emissions and performance.
The optimized bench engine used in this study included engine hardware enhancements that are likely to be used to meet Euro 6 emissions limits and beyond, in part by operating under advanced combustion conditions, at least under some speed and load conditions. The engine enhancements included high fuel injection pressures, high EGR levels and charge cooling, and closed loop combustion control to ensure a constant combustion phasing with different fuels. With these modifications, it was found that the engine could run on a wide range of fuel properties.
The results of the bench engine study were used to guide testing of the same fuels in a demonstrator vehicle equipped with the same advanced combustion engine technologies. These tests assessed the emissions and fuel consumption performance in the European regulatory test cycle. Results are presented from both the bench engine and demonstrator vehicle.