Abstract: Method of and apparatus for adapting slip threshold values for a propulsion slip and/or braking slip control system to the existing tires of a motor vehicle. Here, the instantaneously effective coefficient of friction between vehicle and road is determined from the measured values of the vehicle speed and vehicle longitudinal acceleration from a graph, and with the predetermined value or the predetermined function for the slip thresholds being substituted or corrected by the slip values measured at the driven wheels by use of an operational state defined by a measurement window of a performance graph.