1. A method for consistent bidirectional analysis of engine characteristics map data representing interlinked technical variables (trq, q, n) in an engine characteristics map wherein first a characteristic curve ( 40 ) representing the interdependence of two of the technical variables (trq, q, n) is determined, a constant value being preselected for each of the other technical variables (trq, q, n) and the characteristic curve thus determined being used as the basis for additional conversion calculations in bidirectional analysis of the particular engine characteristics map.