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Vehicular ammonia emissions are currently unregulated, even though ammonia is harmful for a variety of reasons, and the gas is classed as toxic. Ammonia emissions represent a serious threat to air quality, particularly in urban settings; an ammonia emissions limit may be introduced in future legislation. Production of ammonia within the cylinder has long been known to be very limited. However, having reached its light-off temperature, a three-way catalyst can produce substantial quantities of ammonia through various reaction pathways. Production of ammonia is symptomatic of overly reducing conditions within the three-way catalyst (TWC), and depends somewhat upon the particular precious metals used. Emission is markedly higher during periods where demand for engine power is higher, when the engine will be operating under open-loop conditions.

Due to concern over emissions of greenhouse gases (GHG; particularly carbon dioxide - CO2), energy consumption and sustainability, many jurisdictions now regulate fuel consumption, fuel economy or exhaust emissions of CO2. Testing is carried out under laboratory conditions according to local or regional procedures. However, a harmonized global test procedure with its own test cycle has been created: the World Harmonized Light Vehicles Test Cycle - WLTC. In this paper, the WLTC is compared to the New European Driving Cycle (NEDC) and the FTP-75 cycle used in the USA. A series of emissions tests were conducted at BOSMAL on a chassis dynamometer in a Euro 6-complaint test facility to determine the impact of the test cycle on CO2 emissions and fuel consumption. While there are multiple differences in the test cycles in terms of dynamicity, duration, distance covered, mean/maximum speed, etc, differences in results obtained over the three test cycles were reasonably limited.

In this study, two vehicles were tested under real driving conditions with gaseous exhaust emissions measured using a portable emissions measurement system (PEMS). One of the vehicles featured a hybrid powertrain with a spark ignition internal combustion engine, while the other vehicle featured a non-hybrid (conventional) spark ignition internal combustion engine. Aside from differences in the powertrain, the two test vehicles were of very similar size, weight and aerodynamic profile, meaning that the power demand for a given driving trace was very similar for both vehicles. The test route covered urban conditions (but did include driving on a road with speed limit 90 km/h). The approximate test route distance was 12 km and the average speed was very close to 40 km/h.

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).

This paper reviews the exhaust emissions from direct injection (DI) diesel engines in the initial period following start-up. The tests were undertake in “cold start” mode (the temperature of the cooling water and lube oil being equal to the ambient temperature) and “warm start” modes (after achieving a state of equilibrium). The results from both states are compared. Exhaust emissions in the period from cold start is very important and must be improved in order to satisfy present day standards worldwide. A significant emission decrease during cold start can be achieved by incorporating selective fuel cut-off during the few seconds directly after beginning of engine crank. Compared to the acceptable gaseous pollutant concentrations, it was observed that an almost 50% reduction in hydrocarbon emission and a 30% reduction in carbon monoxide emissions were obtained (3 minutes of idle run).

This paper evaluates the possibility of using bioethanol blends (mixtures of gasoline fuel and ethanol derived from biomass) of varying strengths in an unmodified, small-displacement European Euro 5 light-duty gasoline vehicle. The influence of different proportions of bioethanol in the fuel blend (E5, E10, E25, E50 and E85) on the emission of gaseous pollutants, such as: carbon monoxide, hydrocarbons, oxides of nitrogen and carbon dioxide was tested at normal (22°C) and low (-7°C) ambient temperatures for a light-duty vehicle during the NEDC cycle on a chassis dynamometer. Engine performance metrics were also tested. All test results are presented in comparison to standard European gasoline (E5). Tailpipe emission data presented here suggest that modest improvements in air quality could result from usage of low-to-mid ethanol blends in the vehicle tested.

The paper evaluates the possibility of using different biodiesel blends (mixture of diesel fuel and Fatty Acid Methyl Esters) in modern Euro 4/ Euro 5 direct-injection, common-rail, turbocharged, light-duty diesel engines. The influence of different quantity of RME in biodiesel blends (B5, B20, B30) on the emission measurement of gaseous pollutants, such as: carbon monoxide (CO), hydrocarbons (HC), oxides of nitrogen (NOx), carbon dioxide (CO2) and particulate matter (PM) for light-duty-vehicle (LDV) during NEDC cycle on the chassis dynamometer as well as engine performance and reliability in engine dyno tests were analysed. All test results presented have been to standard diesel fuel. The measurement and analysis illustrate the capability of modern light-duty European diesel engines fueled with low and medium percentages of RME in biodiesel fuel with few problems.

The subject of exhaust particulate emissions from road vehicles continues to gain attention and further, more stringent legislative demands are expected in this area. While the European Union has been at the forefront in recent decades, other jurisdictions are making progress towards more comprehensive control and limitation of exhaust particulate. This technical overview examines past, current and likely future (Euro 7) legislative requirements and also presents sample results from a range of vehicle types, in order to make comparisons and discuss the impact of expected regulatory updates. The impacts of powertrain trends, including hybridization, on exhaust particulate emissions and their control are briefly analyzed. Regulatory trends including the intention to move the lower boundary of the size range considered from 23 nm to 10 nm and the elimination of fuel- and technology-specific limits on particulate emissions are discussed and their implications analyzed.

The aim of this paper was to describe a method of accelerated three way catalytic converter (TWC) ageing performed on the engine test bed for European On Board Diagnostics (EOBD) monitoring purposes and screening of different catalysts solutions. To accelerate the catalyst ageing process, the exhaust gas temperature was elevated to a range 1000 - 1200°C, which is typical for an ageing cycle performed using ovens. Catalyst emissions performance was checked at new condition (after degreening) and subsequently at predefined ageing intervals, based on the oxygen storage capacity (OSC) evaluation. The emission tests were performed in the laboratory on the chassis dynamometer using legislative cycles. The accelerated ageing method was found to be of use for verifying the EOBD functionality under vehicle operation with a degraded catalyst substrate.

The aim of this paper is to analyse the results of regulated and unregulated emissions and carbon dioxide (CO2) emissions of passenger cars equipped with compression-ignition engines that meet the emission Euro 6d standards. Both test vehicles featured selective catalytic reduction (SCR) systems for control of oxides of nitrogen (NOx) and one vehicle also featured a passive NOx absorber (PNA). Research was performed using the current European Union exhaust emission test methods for passenger cars (Worldwide harmonized Light vehicles Test Procedures (WLTP)). Emission testing was performed on a chassis dynamometer, within a climatic chamber, at two different ambient temperatures: 23°C (i.e. Type I test) and -7°C (known as a Type VI test - currently not required for this engine type according to EU legislative requirements).

Diesel (compression ignition, CI) engines are increasingly exploited in light-duty vehicles, due to their high efficiency and favorable characteristics. Limited work has been performed on CI cold-start emissions at low temperatures. This paper presents a discussion and a brief literature review of diesel cold-start emissions phenomena at low ambient temperatures and the results of tests performed on two European light-duty vehicles with Euro 5 CI engines. The tests were performed on a chassis dynamometer within an advanced climate-controlled test laboratory at BOSMAL Automotive Research and Development Institute, Poland to determine the deterioration in emission of gaseous (HC, CO, NOx, CO2) and solid (PM, PN) pollutants following the EU legislative test procedure (testing at 20°C to 30°C and at -7°C, performed over the NEDC). The tests revealed appreciable increases in emissions of regulated pollutants.

Carbon dioxide (CO2) is one of the basic greenhouse gases and according to some opinions their influence upon warming the earth climate is significant. Acceptance of this prognosis has lead to worldwide legislative limitation covering all CO2 emitting engines. The paper reviews the relationship between CO2 emissions and fuel consumption in a range of automobiles (with SI and CI engines) presented for type approval over last four years (1996-1999). The paper presents an analysis of the results of an examination of the CO2 emission and the fuel consumption of more like 150 automotive vehicles (M1 and N1 categories), European, Japanese/Korean manufacturer and the US. The procedures used in the examination for approval in the presented scope have been described and several results of these examinations conducted in Poland in accordance with the requirements of the Regulations No. 101 ECE UNO (directive 93/116 EC) have been evaluated.

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.

This paper evaluates the accuracy of emission measurement of regulated gaseous pollutants from vehicles tested on chassis dynamometers. The paper describes sources of error during exhaust emissions measurement. A model of uncertainty using statistical analysis and standard uncertainty propagation techniques has been used. The model, based on individual uncertainties of different instruments used in the measurement process, as well statistical analysis evaluating uncertainties resulting from the errors introduced by the vehicle, the driver and the chassis dynamometer were all used to compute the total uncertainty of the emission measurement. The paper shows that current CVS system and analytical techniques used to measure exhaust emissions are not sufficient to meet Euro 5 standards. Either an improvement to the CVS system or the development of a new emission sampling system is a prerequisite to measure the emissions from vehicles complying with Euro 5 or SULEV.

The motor vehicle is one of the main sources of pollutant emissions, especially in urban areas. Environmentally friendly fuels are regarded as very effective means to decrease emissions. With regard to diesel engines, the reduction in nitrogen oxides and particulates are major problem areas. Although the fuel influence on NOx is comparatively low, the composition and parameters of diesel fuel have a big influence on particulate emissions and composition. Sulphur content is one of fuel proprieties, which has the most considerable influence on particulates. This paper describes results of the research on particulate emissions from diesel engines fuelled with research fuels of differing sulphur content. The sulphur content of the research fuels varied from 2000 ppm through 350 ppm (EURO III) and 50 ppm (EURO IV limit, which will be in force in the European Community from 1 January 2005) up to less than 5 ppm.

Ammonia is a reactive nitrogen compound (RNC - nitrogen-based gaseous molecules with multiple adverse impacts on human health and the biosphere). A three-way catalyst can produce substantial quantities of ammonia through various reaction pathways. This study presents a brief literature review, and presents experimental data on ammonia emissions from seven Euro 5 passenger cars, using different gasoline fuels and a CNG fuel. All vehicles were tested on a chassis dynamometer over the New European Driving Cycle. For six of the vehicles, ammonia was quantified directly at tailpipe (using two different analyzers); emissions from one vehicle were subjected to Fourier Transform Infra-Red (FTIR) analysis. Emissions of ammonia from these vehicles were generally low in comparison to other chassis dynamometer studies, perhaps attributable to the favorable laboratory test conditions and the age of the vehicles.

A vital question for car manufacturers in countries where the temperature over night falls below freezing, is the significant increase of CO (carbon monoxide) and HC (hydrocarbon) emissions during the start and warm-up of spark ignition engines. ECE (Economic Commission for Europe) (UDC) (Urban Driving Cycle) cycles, divided into elementary phases, have been used to determine the level of harmful CO and HC emissions and fuel consumption in the cold start and warm up phase. Tests were undertaken on cars conditioned in temperatures ranging from +22°C to -15°C have shown significant increases in CO and HC as the temperature decreases.

This paper reviews the exhaust emissions from direct injection diesel engines in the initial period following startup. The tests were undertake in “cold start” mode (temperature of cooling water and lube oil equal ambient temperature) and “warm start” modes (after getting equilibrium state). Both results were compared. Exhaust emissions in the period of run from cold start to warmed-up is very important to satisfy present day standards worldwide.

The great reduction in future diesel engine emission limits, especially PM and NOx, forces one to develop means to comply with stringent legislation. Environmentally friendly fuels are regarded as a very effective means to decrease emissions. Although the emission reduction is less than could be achieved by the most modern engine technology or alternative fuels, the immediate net effect of reformulated diesel fuel on emissions is significant, as it takes place over the whole vehicle population. The experimental results presented in this paper were obtained within a research program investigating the effect of different fuels upon emissions from compression-ignition automotive engines. The research were carried out in the laboratories of the BOSMAL Automotive R & D Centre in co-operation to Institute of Internal Combustion Engines at Poznan University of Technology. The partial results of this research program were presented in SAE Paper 2002-01-2219.

The European driving cycle, deleting the first 40 seconds of idle after the start up phase, and the US FTP 75 cycle are compared in this paper. The paper presents an analysis of emission tests for CO, HC and NOx measured during tests performed on a chassis dynamometer under laboratory conditions. The tests are reviewed and the results discussed. The objective of the study was to determine the influence of the test cycle on the measured emission of CO, HC and NOx, and the changes of fuel consumption at the initial phase of engine operation. Differences in catalyst warm up rates when running NEDC, ECE + EUDC and FTP 75 cycles are demonstrated. Methods of reduction in these harmful emissions and the results of tests with new technologies targeted at the reduction of CO, HC and NOx under cold start are also discussed.