Aspects of the Future Convergence of Spark-Ignition and Compression-Ignition Engines

High power-to-volume ratio and significant reduction of fuel consumption and pollution are paramount development targets for both SI and CI engines for automotive propulsion. Their implementation within a broad function range generated modular technical solutions - as elements of a general down-sizing platform - which are successful applicable in both SI and CI engines. The effects of such techniques, from super-charging or turbocharging, variable valve control and direct injection up to exhaust gas recirculation, autoignition-generated combustion and catalyst system indicate a merging which causes a basic discussion about the convergence of SI and CI engines.