Abstract: The present invention relates to a method for adjusting a mass flow of an exhaust gas return of an internal combustion engine, taking into consideration a NOx behavior, wherein a controlling system provides a coupling of a virtual NOx determination with a real NOx control. Furthermore, an internal combustion engine with appropriate controlling means is proposed.

Abstract: The task of the present invention is to improve a variable valve operating mechanism in order to support different operating ranges of a motor vehicle through optimized operation of the reciprocating internal combustion engine. This task is achieved with a reciprocating internal combustion engine of a motor vehicle with the features of Claim 1, with a method for the cyclical-synchronous switching with the features of Claim 12, and also with a method for operating a reciprocating internal combustion engine of a motor vehicle with the features of Claim 13. Additional advantageous configurations and refinements are specified in each dependent claim.