Abstract
One objective is in the forefront when adopting the gasoline direct-injection engine in the passenger car: minimum fuel consumption. Its scope for extreme lean-burn operation and thus for the avoidance of throttling losses indicate that the DI principle is the most effective individual fuel consumption reducing measure that can be applied to the spark-ignition engine and an excellent basis for a fuel-saving concept. In addition, the DI principle has potential advantages in full-load operation and with regard to emissions during warm-up. Its full thermodynamic potential cannot be exploited today in vehicle operation, as a conflict of objectives exists between minimum fuel consumption and the settings that yield the lowest emission [2,3]: the achievement of the DI engine full potential as a lean-burn unit still exhibits scope for improvement in terms of the combustion process, peripheral systems, after-treatment of the exhaust gas and the nature of the fuel.