<div class="htmlview paragraph">Since the available combination of equations describing the kinetic reactions during diesel combustion a) is complicated, b) falls short in predicting actual NO-emissions, an attempt is made with a simplified model to correlate the squared temperature profile of the cycle over time, integrated above the level of a significant threshold temperature, with NO_x formation. This rating permits the evaluation of cycle parameters, like compression ratio, ignition timing, heat release and others, regarding their effect on the compromise between acceptable emission and cycle efficiency.</div> <div class="htmlview paragraph">The underlying working theories compare and complement existing analytical models of diesel ignition, combustion and soot emission.</div>