Fuel economy, emissions and noise of multi-spray light duty DI diesels–current status and development trends

The current status and development trends of light duty diesel engines equipped with a multi-spray direct injection combustion system are described. Fuel consumption maps of a naturally aspirated and a turbocharged engine show that competitive performance and best fuel economy can be achieved. As a means for the reduction of combustion noise a “split injection device” is installed in the high pressure part of the fuel system. It permits a reduction of the amount of fuel injected during the ignition delay and consequently reduces the rate of pressure rise and maximum cylinder pressure. In addition, also a reduction of exhaust emissions is experienced. Advanced piston technology is presented as a feature for a further improvement of performance and fuel economy.