System for analyzing an energy efficiency of a vehicle with at least one drive device, which is set up to generate mechanical drive force by energy conversion, comprising: a first device, in particular a sensor, adapted to acquire a first set of data of at least one first parameter suitable to characterize an energy consumed by the vehicle; a second device, in particular a sensor, adapted to acquire a second set of data of at least one second parameter suitable to characterize a driving resistance which the vehicle overrides; a third device, in particular a sensor, set up for acquiring a third data set of at least one third parameter which is suitable for characterizing at least one driving state of the vehicle; a first comparison device, in particular part of a data processing device, set up for comparing the values of the third data set with predefined parameter ranges which correspond to at least one driving state; an assignment device, in particular part of a data processing device, set up for assigning the values of the first data record and the values of the second data record to the at least one driving state present in each case; a processing device, in particular part of a data processing device, arranged to determine at least one characteristic value characterizing the energy efficiency of the vehicle on the basis of the first data set and the second data set as a function of the at least one driving state; a selection device arranged to determine at least one device A whose energy consumption is disregarded when determining the at least one characteristic value of the energy efficiency of the vehicle; and a fourth means adapted to detect a further second parameter characterizing the energy consumption of the at least one device A, wherein the processing means is further set up to adjust the energy consumption of the vehicle for the energy consumption of the at least one device A. a first device, in particular a sensor, adapted to acquire a first set of data of at least one first parameter suitable to characterize an energy consumed by the vehicle; a second device, in particular a sensor, adapted to acquire a second set of data of at least one second parameter suitable to characterize a driving resistance which the vehicle overrides; a third device, in particular a sensor, set up for acquiring a third data set of at least one third parameter which is suitable for characterizing at least one driving state of the vehicle; a first comparison device, in particular part of a data processing device, set up for comparing the values of the third data set with predefined parameter ranges which correspond to at least one driving state; an assignment device, in particular part of a data processing device, set up for assigning the values of the first data record and the values of the second data record to the at least one driving state present in each case; a processing device, in particular part of a data processing device, arranged to determine at least one characteristic value characterizing the energy efficiency of the vehicle on the basis of the first data set and the second data set as a function of the at least one driving state; a selection device arranged to determine at least one device A whose energy consumption is disregarded when determining the at least one characteristic value of the energy efficiency of the vehicle; and a fourth means adapted to detect a further second parameter characterizing the energy consumption of the at least one device A, wherein the processing means is further set up to adjust the energy consumption of the vehicle for the energy consumption of the at least one device A.