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There is a growing appreciation for using buses powered by alternative fuels in urban transport. Considered as such are city bus with engines fuelled with LNG and hybrid bus. This article, as shown above, provides a comparison of road exhaust emissions from three city buses: one with a CI engine fuelled with diesel fuel, and the other with a SI engine fuelled with LNG and Hybrid bus. Both vehicles (CI and LNG) conformed to Euro VI emission standard (hybrid bus EEV), and the tests were carried out in real traffic conditions. Equivocal opinions about differences in emissions from those types of buses, among others - CO2 and NOx emissions, were the underlying cause of the tests. The comparative study was carried out along the same urban routes during bus trips over the following days in similar traffic conditions. Exhaust road emission was determined based on the vehicle's curb weight and route length, and operating fuel consumption.

Non-plugin hybrids represent a technology with the capability to significantly reduce fuel consumption (FC), without any changes to refuelling infrastructure. The EU market share for this vehicle type in the passenger car segment was 3% in 2018 and this powertrain type remains of interest as an option to meet the European Union (EU) fleet average CO2 limits. EU legislative procedures require emissions limits to be met during the chassis dynamometer test and in the on-road real driving emissions (RDE) test, while official CO2/FC figures are quantified via the laboratory chassis dynamometer test only. This study employed both legislative test procedures and compared the results. Laboratory (chassis) dynamometer testing was conducted using the Worldwide Harmonised Light Vehicles Test Procedure (WLTP). On-road testing was carried out in accordance with RDE requirements, measuring the concentration of regulated gaseous emissions and the number of solid particles (PN).

In order to measure the concentration of toxic compounds a mobile analyzer for toxic tests SEMTECH DS by SENSORS Inc. was used. In the study the results of the vehicle emission tests in the road conditions were presented as this was the only way to obtain the information on real vehicle emissions. They include information on the emissivity of the vehicles in operation and deal with the real conditions of the vehicle motion. Reliable measurement results were obtained which were verified in simulated conditions on a chassis test bed. The obtained data were used to specify the dependence characteristics for the influence of the dynamic engine properties on the harmful compound emissions. The dynamic engine properties were indirectly taken into account using all the speed range and the range of acceleration calculated for the city traffic in order to prepare a matrix of emission intensity.

In order to measure the concentration of exhaust emissions a mobile emission testing analyzer SEMTECH DS by SENSORS Inc was used. In the study the results of the vehicle emission tests in the road conditions were presented, as this was the only way to obtain the information on real vehicle emissions. They include information on the emissivity of the vehicles in operation and deal with the real conditions of the vehicle in motion. Reliable measurement results were obtained which were verified in simulated conditions on a chassis test bed. The obtained data were used to specify the dependence characteristics for the influence of the dynamic engine properties on the exhaust emissions. The dynamic engine properties were indirectly taken into account using all the speed range and the range of acceleration calculated for the city traffic in order to prepare a matrix of the emission intensity.

The tests related to the exhaust emissions from non-road vehicles are currently performed on a chassis dynamometer under the name of NRSC (ISO 8178) and NRTC. In light of the growing requirements related to the environment protection in transport the authors recommend determining the exhaust emissions through real vehicle operating conditions. The tests carried out under real operating conditions could be used for the process of optimization of future power trains of regular road vehicles and non-road vehicles. What is more, these tests should be taken into account in the works on the changes of the legislation related to the emission limits from combustion engines. The paper presents the results of the tests on the exhaust emissions from an agricultural harvester engine and a tractor engine in real operating conditions. The harvester operation during the test consisted in crops collection from the field and the tractor operation during the test consisted in plowing.

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.

The paper presents the results of tests on a combustion engine of an armored modular vehicle 8x8 Rosomak under combat simulating conditions. For the measurements of the toxic compounds a portable SEMTECH DS analyzer by SENSORS was used. The analyzer allowed a measurement of toxic compounds at the same time measuring the mass flow rate of the exhaust gases. The analysis of the PM emission was performed based on the measurement of the size of the particulate matter (analyzer 3090 EEPS - Engine Exhaust Particle Sizer™ Spectrometer - by TSI Incorporated) and counting of the particles (analyzer Particle Counter by AVL). The measurements of CO, HC, NOx, PM and fuel consumption were performed under the conditions of combat simulation and in the overboost mode. Based on the obtained results, an analysis of the engine and vehicle operation was performed and the on-road and unit exhaust emissions as well as on-road and unit fuel consumption were compared.

The paper presents results of the road tests of exhaust gas emissions of vehicles of different emission classes (Euro 4 and Euro 5, with different mileage), fuelled with compressed natural gas. The tests of exhaust emissions were conducted on parts of the road with different characteristics of the traffic intensity. For each phase of the tests, the characteristics of the test run and the value of exhaust gas emissions were determined. To measure the exhaust emission the Portable Emission Measurement System (PEMS) was used.

This paper discusses the legislative situation regarding type approval of plug-in hybrid vehicles (also known as off-vehicle charging hybrid-electric vehicles, OVC-HEV) in the range of exhaust emissions and fuel consumption. A range of tests were conducted on two Euro 6d-complaint OVC-HEVs to quantify emissions. Procedures were based on EU legislative requirements. For laboratory (chassis dyno) testing, two different test cycles and three different ambient temperatures were used for testing. Furthermore, in some cases additional measurements were performed, including measurement of emissions of particulate matter and continuous analysis of regulated and unregulated pollutants in undiluted exhaust. Consumption of electrical energy was also monitored. On-road testing was conducted on the test vehicle tested on the chassis dyno in the tests mentioned above, as well as on a second OVC-HEV test vehicle.

This paper discusses the importance of the inclusion of emissions from the cold start event during legislative on-road tests on passenger cars (RDE - real driving emissions tests conducted under real-world driving conditions, as defined by EU legislation). Results from a recently-registered gasoline-powered vehicle are presented, with the main focus on the comparison of exhaust emission results: excluding/including the cold start during the initial phase of the RDE test. Cold start is the most challenging aspect of emissions control for vehicles with spark ignition engines and the inclusion of the cold start event in RDE test procedure has wide-ranging implications both for the testing process and compliance with RDE legislation via optimisation of aftertreatment systems and the engine calibration. In addition to some theoretical arguments, the results of an RDE-compliant test performed using the aforementioned procedures are presented.