Diesel innovation and leadership in core technological and scientific competencies are the key drivers for European competitiveness. In this context, diesel engine improvements towards more efficient and less polluting vehicles play a critical role in the competitiveness of the European car industry and in the long-term sustainable growth and job preservation in Europe, along with the necessary improvement of air quality and reduction of health effects. In the next ten years, it is anticipated that a smooth transition from conventional engines to new diesel technologies will happen (from conventional to partially homogeneous and then to finally homogeneous over a wide range of operating points). Diesel Homogeneous Charge Compression Ignition (HCCI) combustion processes are seen as a promising way to meet the future environmental challenges, which will have to achieve both significantly lower pollutant emissions and fuel consumption.

With these concepts, NOx and PM emissions are simultaneously drastically reduced avoiding the installation of a complex and costly NOx specific after treatment. The main drawback of this concept is that the level of low-temperature related emissions, i.e. CO and HC, can increase by several orders of magnitude. This implies that conventional oxidation catalysts' technologies, currently used on Euro IV compliant vehicles, are no more able to convert these harmful emissions because of the saturation of the active catalytic sites.

As a result, such increased CO and HC emissions have to be reduced to safe levels using innovative catalysts or emergent technologies, which have to be characterised by a different reaction kinetic, so are less dependant on the pollutants' concentration. It is also admitted that such innovative combustion processes will merge with an increasingly wider diffusion of new fuel properties and renewable formulations, so that will be helpful to enlarge the engine running range (EUCAR RENEW project). The impact of these new fuel formulations on next-generation after treatment processes will also have to be investigated.