Determining the environmental indicators for vehicles of different categories in relation to CO2 emission based on road tests

The article discusses the possibility of determining the environmental indicators for vehicles of different categories in relation to CO₂ emissions. These are called toxicity indicators because they concern the compounds: CO, THC and NO_x. Three Euro V compliant vehicles with different propulsion systems types were used for the study: a 0.9 dm³ urban passenger car with a SI engine and a start-stop system, a 2.5 dm³ off-road vehicle with a CI engine, and a city bus with a hybrid drive system in series configuration and a CI engine with a displacement of 6.7 dm³. Measurements were made in actual operating conditions in the Poznan agglomeration using a portable emissions measurement system (PEMS). The paper presents the characteristics of the operating time shares of vehicles and propulsion systems as well as CO₂ emissions depending on the engine load and crankshaft rotational speed for individual vehicles. The determined toxicity indicators allowed to indicate their usefulness, to make comparisons between tested vehicles, and to identify directions for further work on the application and interpretation of these indicators.