One of the environmental aims of the European Union is to achieve climate neutrality by 2050. According to European Parliament data, transport emissions accounted for about 25% of global carbon dioxide emissions in 2016, in which road transport had the largest share (approximately 72%). This phenomenon is particularly visible in urban agglomerations. The solution examples are the popularization of hybrid vehicles and the development of electromobility. The aim of this paper is an assessment of the energy consumption and exhaust emissions from passenger cars fitted with different powertrains in actual operation. For the tests, passenger cars with conventional engines of various emission classes were used as well as the latest hybrid vehicles and an electric car. It enabled a comparative assessment of the energy consumption under different traffic conditions, with particular emphasis on the urban phase and the entire RDE (Real Driving Emissions) test. The results were analyzed to identify changes in these environmental factors that have occurred with the technical advancement of vehicles. The lowest total energy consumption in real traffic conditions is characteristic of an electric vehicle; the plug-in hybrid vehicle with a gasoline engine is about 10% bigger, and the largest one is a combustion vehicle (30% bigger than an electric vehicle). These data may contribute to the classification of vehicles and identification of advantages of the latest developments in conventional, hybrid, and electric vehicles.

This paper reviews the emissions from direct injection (DI) diesel engine in the initial period of controlled engine operation following start-up. The tests were undertaken in „cold start” mode (temperature of cooling water and lube oil equal to ambient temperature) and „warm start” mode* (after attaining a state of equilibrium). Both results were compared.

This paper presents a study of passenger cars in terms of emissions measurements in tests conducted under real driving conditions (RDE - Real Driving Emissions) by means of PEMS (Portable Emission Measurement System) equipment. A special feature of the RDE tests presented in this paper is that they were performed under Polish conditions and the specified parameters may differ from those in most other European Union countries. Emission correction coefficients have been defined, based on the test results, equal to the increase (or decrease) of driving emissions during the laboratory (‘chassis dyno’) test or during normal usage in relation to the EU emission standards (emission class) of the vehicle. In relation to the fact that at present emissions limits specified for chassis dynamometer testing are currently used for RDE testing, in this paper we present those limits, proposing that they be accompanied by conformity range coefficients defining the “safety factor” for exhaust emissions measured during chassis dyno tests. On the basis of the coefficients defined in this paper, the ecological parameters of vehicles of various emission classes and design parameters (fuel supply systems) are presented. The test results and defined emission correction coefficients permitted an ecological assessment of vehicles of various emission classes to be conducted, and in the meantime they help with pre-emptive actions in terms of reducing emissions of some pollutants from passenger vehicles. The measurement methods applied here can also be used for other types of vehicles (e.g. heavy duty, off-road), or alternative fuel vehicles.

E3S Web of Conferences, open access proceedings in environment, energy and earth sciences