The article presents a proprietary method for assessing the environmental impact of a hybrid rail vehicle utilizing both electric traction and an internal combustion engine for propulsion. Current efforts aimed at decarbonizing transportation have led to an increase in the production of electric vehicles and the adoption of such powertrains. However, the energy required to power these vehicles still predominantly comes from fossil fuels, which contribute to global emissions of toxic compounds. The lack of regulatory standards for measuring energy consumption hinders an accurate evaluation of the environmental impact of such vehicles. The proposed testing cycle consisted of several repeated runs of the vehicle on a specialized test track. During the actual runs, measurements were taken of the emissions of toxic compounds from the exhaust systems, as well as the vehicle's electrical energy consumption. The real-world energy consumption was then compared to data on emissions of toxic compounds from the largest power plants operating in Poland. The results of the analysis suggest that current internal combustion engines, which comply with the latest emission standards, contribute less to global air pollution than vehicles powered by electricity generated from fossil fuels. There is a need for continued research into the energy consumption of electric vehicles to accurately assess their real environmental impact. Additionally, further research should be conducted on real operating conditions of exhaust emissions.