The work presents experimental results of performance tests and theoretical calculations for the thermoelectric generator TEG fitted in the exhaust system of a 1.3 dm3 JTD engine. Benchmark studies were carried out to analyze the performance of the thermoelectric modules and total TEG efficiency. Additionally the investigation of combustion engine’s power drop casued by exhaust gasesflow resistance is presented. The detailed studies were performed using a new prototype of the thermoelectric generator TEG equipped with 24 BiTe/SbTe modules with the total nominal power of 168 W. The prototypical device generates maximal power of200 Wfor the exhaus gases massflow rate of 170 kg-h-1 and temperature of280 oC. Power drop caused by the flow resistance of gases ranges between 15 and 35 mbarfor mass flow rate 100-180 kg-h-1. We predict that the application of the new thermoelectric materials recently developed at AGH would increase the TEG power by up to 1 kW, would allow the increase of the powertrain system efficiency by about 5 %, and a corresponding reduction of C02 emission.