Increasingly stringent emissions legislation coupled with the need to reduce the consumption of the fossil based fuels is driving the development of engines and their systems. In the past, the choice of emissions aftertreatment system affected the combustion system layout and development and this in turn influenced the demands placed on the fuel injection system. With such legislation as Euro IV, EPA10, J-PNLT and Stage IV/Tier 4 emissions requirements to fulfil, the demands on the fuel injection system are becoming more severe and increasingly high injection pressures and system flexibility are being requested. In addition, with ever increasing fuel costs and diminishing resources, attention is being focussed on system efficiency as well as the compatibility with different fuels and blends. Based on experience with different injection systems and emissions scenarios, the requirements for fuel injection systems to meet future legislation are described and analysed.
