Method for collecting data from a motor-driven vehicle that is provided with a microprocessor having memory for storing a particular quantity of data. The data is provided by a number of sensors connected to the vehicle and its motor and is recorded and compiled into a specific data file upon each recording occasion when it its ascertained that conditions are fulfilled for recording a data file. This is recorded as a non-erasable reference data file. Upon subsequent occasions when the conditions are fulfilled, a number of successively erasable data files are successively recorded and stored within the predetermined quantity of data.