In modern Diesel engines at the best point a theoretical thermal efficiency up to 50% can be reached and, with supercharging, it is possible to obtain mean effective pressures comparable to those of Otto engines. In spite of this successful development, power density, partload behavoir, pollutant emissions and noise levels are still too high to fulfill future environmental demands. With so called hybrid engine concepts, a combination of procedures of Otto- and Diesel engines, so far only a marginal improvement of today's Otto- and Diesel engines could be reached. With a completely new design of stratified charge engines, iniated by pulsed jets generated by combustion of rich mixtures in pre chambers and followed by fireball-combustion of lean mixtures in the middle of the cylinder, surrounded by a layer of inert gas close to the cylinder wall, a quantum transition can be reached with diesel-like stratified charge engines, with which it would be possible to avoid any kind of exhaust gas-after-treatment. Results of computer simulation have shown that two-stroke-engines have the best potential.