One of the most important elements determining the assessment of the quality of trolleybuses and buses in public transport is the operating cost which comprises mainly the cost of power or fuel consumption. The knowledge of economic properties of new vehicles is justified when the decision about their purchase is being made. The information about vehicles which have not been used in the company so far comes mainly from the protocols of homologation tests as well as the opinions of other users. In both cases such knowledge is insufficient against the expected information providing for specific driving conditions in urban traffic. Chosen driving tests applied for the evaluation of energy consumption of trolleybuses and buses operation are presented in the article. Working conditions of the trolleybus were analysed on the basis of the comparative tests of the bus and the trolleybus for a chosen communication line in Lublin. On the basis of the determined characteristics describing working conditions of the vehicles constituting public transport in Lublin, the MPKPL test was drawn up and the analysis of findings was carried out for a chosen communication line.