Due to increasing sales figures, the energy consumption of battery-electric vehicles is moving further into focus. In addition to efficient driving, it is also important that the energy losses during AC charging are as low as possible for a sustainable operation. In many situations it is not possible or necessary to charge the vehicle with the maximum charging power e.g., in apartment buildings. The influence of the charging mode (number of phases used, in-cable-control-box or used wallbox, charging current) on the charging efficiency is often unknown. In this work, the energy consumption of two electric vehicles in the Worldwide Harmonized Light-Duty Vehicles Test Cycle is presented. In-house developed measurement technology and vehicle CAN data are used. A detailed breakdown of charging losses, drivetrain efficiency, and overall energy consumption for one of the vehicles is provided. Finally, the results are discussed with reference to avoidable CO${}_2$ emissions. The charging losses of the tested vehicles range from 12.79 to 20.42%. Maximum charging power with three phases and 16 A charging current delivers the best efficiencies. Single-phase charging was considered down to 10 A, where the losses are greatest. The drivetrain efficiency while driving is 63.88% on average for the WLTC, 77.12% in the “extra high” section and 23.12% in the “low” section. The resulting energy consumption for both vehicles is higher than the OEM data given (21.6 to 44.9%). Possible origins for the surplus on energy consumption are detailed. Over 100,000 km, unfavorable charging results in additional CO${}_2$ emissions of 1.24 t. The emissions for an assumed annual mileage of 20,000 km are three times larger than for a class A+ refrigerator. A classification of charging modes and chargers thus appears to make sense. In the following work, efficiency improvements in the charger as well as DC charging will be proposed.

The search for substitutes for modern fossil fuels incentivises the use of new propulsion systems (hybrid or electric) and the use of new fuels (gaseous, mainly hydrogen). The article discusses the basic issues related to hydrogen fuel: from its extraction, through the discussion of its properties to its use and applications. Analyzes of the energy consumption involved in its extraction or production were presented, classifying hydrogen in those terms. Great emphasis was placed on design solutions for the use of hydrogen in internal combustion engines, together with discussing the concept of its combustion. The methods of storing hydrogen in a condensed and compressed form were also presented, indicating at the same time the most modern solutions available, such as mixed systems – storage in cryo-compressed form. It has been shown that the combustion of hydrogen in internal combustion engines increases their efficiency, and at the same time significantly reduces the exhaust emissions of toxic gases – including the emission of nitrogen oxides.

The real driving emission (RDE) testing for certification of vehicles is performed in conditions that are well defined in legislation. For emissions inventories and for research, the influences of some extended driving conditions on emissions are an interesting issue. In the present work, some examples of RDE results from two common passenger cars with gasoline and diesel propulsion are given. The varying driving conditions were “winter/summer”, “mild/aggressive”, and “higher altitude/slop”. The driving conditions: “winter”, “aggressive”, and “higher slope/altitude” generally require more energy, cause higher fuel consumption, and therefore, higher CO₂-emissions. The condition of “winter driving”, especially in the urban type of operation, may cause some longer phases with not enough warmed-up exhaust aftertreatment and consequently some increased gaseous emissions. The DPF eliminates the nanoparticles (PN) independently on the driving conditions. Nevertheless, the DPF regeneration has an influence on the CO₂-normality of the trip. The CO₂-normality primary tolerance range can also be exceeded with aggressive driving. The elaborated results confirm the usefulness of the existing legal limits for the driving conditions of RDE homologation tests.

Testing of real driving emissions (RDE) offers the opportunity to collect the data about the emissions in special driving, or non-driving situations. These situations are: cold start, warm-up of the engine, stop & go and idling. In the present work, the definitions of the special driving situations were proposed, the emissions of 7 passenger cars (gasoline & Diesel) were extracted from the present RDE data and some special driving situations, particularly the stop & go operation with varying share of idling were reproduced on chassis dynamometer. As expected, the emissions of CO, NOx and PN are in the cold start and in the first part of the warm-up phase (c.a. 25s) considerably higher than in the rest of the investigated urban phase. The singular emitting situations like “stop & go” or idling occur frequently in the warm-up phase, i.e. in the city operation when the engine and the exhaust system are still not warm enough.

Particle number concentration (PN) in vehicle exhaust and ambient air describes the number of ultrafine particles (UFPs) below 500 nm, which are recognized as a toxic and carcinogenic component of pollution and are regulated in several countries. Metal nuclei, ash, and organic matter contribute significantly to the ultrafine particle size fraction and, thus, to the particle number concentration. Exhaust gas filtration is increasingly being used worldwide to significantly reduce this pollution, both on diesel particulate filter (DPF) and gasoline particulate filter (GPF) engines. In recent years, the EU has also funded research projects dealing with the possibilities of retrofitting gasoline vehicles with GPFs. This paper presents the results and compares the PN emissions of different vehicles. An original equipment manufacturer (OEM) diesel car with a DPF is considered as a benchmark. The PN emissions of this car are compared with a CNG car without filtration and with gasoline cars equipped with GPFs. It can be concluded that the currently used GPFs still have some potential to improve their filtration efficiency and that a modern CNG car would still have remarkable possibilities to reduce PN emissions with an improved quality GPF.

Nanoparticles (NP) in the sub-micrometer measuring range are invisible. NPs from combustion processes, consisting of carbon, metal and ash nuclei and organic substances, enter the human organism through the olfactory nerves and lungs, where they can have various effects (toxic, carcinogenic, mutagenic), some of which are long-lasting (chronic). These invisible nanoparticles were identified in the second half of the last century. Since then, a great deal of research has been carried out in various fields, and nanofiltration has demonstrated and realised ways of efficiently removing nanoparticles. The greatest progress has been made in the aftertreatment of exhaust gases from combustion engines. Nevertheless, further efforts are needed here, as in other areas such as indoor and outdoor air pollution control. The authors have been involved in important stages of these developments and, in this article, they attempt to provide a brief review and a desirable outlook, along with a few examples. In summary, it can be said that all types of engines and numerous other anthropogenic sources emit harmful nanoaerosols. During the pandemic, it was proven that nanofiltration used for exhaust gas aftertreatment in engines effectively eliminates bio-nanoaerosols, i.e. viruses and larger pathogens such as bacteria, fungi, allergens and others. We are all constantly surrounded and permeated by nanoaerosols and must live in symbiosis with them. It is therefore advisable for society to gain a better understanding of this issue, take it seriously and be even more concerned about the quality of the air surrounding the general population.