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Particulate emissions from Gasoline Direct Injection (GDI) engines have been an important topic of recent research interest due to their known environmental effects. This review paper will characterise the influence of different gasoline direct injection fuel systems on particle number (PN) emissions. The findings will be reviewed for engine and vehicle measurements with appropriate driving cycles (especially real driving cycles) to evaluate effects of the fuel injection systems on PN emissions. Recent technological developments alongside the trends of the influence of system pressure and nozzle design on injector tip wetting and deposits will be considered. Besides the engine and fuel system it is known that fuel composition will have an important effect on GDI engine PN emissions. The evaporation qualities of fuels have a substantial influence on mixture preparation, as does the composition of the fuel itself. Recently a number of studies have attempted to link fuel composition with PN emissions, developing a variety of indices including the PM index (Aikawa et al.) and the PN index (Leach et al.). An extensive literature search has been carried out and the PN index evaluated against these data. In addition the PM index and PN index are compared. The results of the review show that the Aikawa index should be applied when the fuel quality is known by lab reports, whereas the Leach index is relevant when only minimal information about a fuel is known, even the latter giving a relatively good prediction of PN emission trends from fuels in GDI engines.

Diesel engines have traditionally been favoured in heavy-duty applications for their fuel economy, robustness, reliability and relative lack of fuel sensitivity. Recently it has seen a growth in its popularity in light duty applications due particularly to its fuel efficiency. However, as the engine technology and particularly the fuel injection equipment has evolved to meet ever stricter emissions legislation the engines have become more sensitive to deposit formation resulting from changes in fuel quality. This paper reviews bouts of concern over diesel fuel injector deposits, possible causes for the phenomenon and test methods designed to screen fuels to eliminate problems.

Recent developments in diesel engines and fuel injection equipment combined with the change to ULSD and bio-blends have resulted in increased reports regarding deposits within injectors and filters. A review of known fuel degradation mechanisms and other relevant chemistries suggests the effects of high pressure and high shear environments should be examined as the most probable causes of increasing deposit formation. Existing fuel quality tests do not correlate with reported fouling propensity. Analytical studies have shown that there are only subtle chemical changes for the materials within the standard diesel boiling range. The implications for further scientific study are discussed.

Limited and nonlimited emissions of scooters were analysed during saveral annual research programs of the Swiss Agency of Environment Forests and Landscape (SAEFL, BUWAL) *) . Small scooters, which are very much used in the congested centers of several cities are a remarkable source of air pollution. Therefore every effort to reduce the emissions is an important contribution to improve the air quality in urban centers. In the present work detailed investigations of particle emissions of a Peugeot scooter with TSDI (Two Stroke Direct Injection) were performed. The nanoparticulate emissions with different lube oils and fuels were measured by means of SMPS, (CPC) and NanoMet * ) . Also the particle mass emission (PM) was measured with the same method as for Diesel engines. It can be stated, that the oil and fuel quality have a considerable influence on the particle emissions, which are mainly oil condensates. Not all influences can be explained and more detailed knowledge about the oil composition and about the used additive packages is necessary. The use of non active catalyst leads to strongly increased particle emissions values, both mass and counts. Since the particulate emission of the 2-S consists mainly of lube oil condensates the minimization of oil consumption stays still an important goal.

This paper reports some results on the emission performance of a CR DI diesel engine burning five model diesel fuels. The fuels were prepared by Agip Petroli S.p.A within the PNRA research program, sponsored by Italian Ministry of Environment and were a base fuel, a synthetic fuel and three oxygenated fuels. The engine employed in the tests was a prototype derived from Fiat M724 1910 cc, installed on Fiat Group class C Cars (1350 kg of mass). The prototype complies with EURO3 regulations. Two test points representative of two zones of ECE15+EUDC test cycle were chosen. Thermodynamic variables, emissions and injection systems parameters were recorded. Tests show the further potential of advanced fuels, obtained by blends of reformulated and oxygenated components, in reducing pollutants emissions.

This paper presents a start algorithm that is able to control the air/fuel ratio (AFR) during the cranking phase and immediately hereafter, where the ordinary ?-control is not yet enabled. The control is based on the ion sense principle, which means that a current through the spark plug is measured directly after the spark has disappeared. This current is a measure for the temperature and therefore of the combustion in the cylinder. This is an excellent way to start a CNG (Compressed Natural Gas) engine with unknown gas qualities. A typical example of application is when the vehicle is almost out of fuel and is refueled at a motel stop. The small amount of old fuel that is left in the system will mix with the new fuel resulting in an unknown fuel quality. The control system shall then be able to start the engine directly or after an accommodation over night. During the last condition, the oxygen sensor is still cold and thus not able to correct for fuel quality changes. By using the ion current signal, the start algorithm manages to start the engine with unknown fuel qualities. In addition, the algorithm also manages fuel changes in the period immediately after cranking. The key idea of the presented method is to supply the subsequent cylinders with a step wise changing AFR. A gas injection system that is able to dose cylinders individually is therefore indispensable. Based on the ion current signal, the ''combustion status'' is determined, and the changing AFR is continued or not. Immediately after start, when the engine is running, another algorithm takes over the control to maintain ignitable air/fuel ratios. Once the oxygen sensor is heated up, the normal ?-control can take over the task to correct for a changed gas quality. All experiments are performed on a 5-cylinder 2.0 ltr turbo charged Volvo production engine converted from gasoline to CNG operation. It is equipped with a newly developed sequential gas injection system, featuring injectors with electrical properties of gasoline injectors.\END

This paper presents the performances of a modern DI diesel engine, equipped with a common-rail injection system, fed on blends of an advanced diesel fuel (base fuel) and Diethylene- Glycol-Dimethyl-Ether (Diglyme - C6H14O3). The base fuel was a reformulated diesel fuel with low aromatic and sulfur content. Three blends with different volumetric percentage of Diglyme (10, 20 and 30%) in the base fuel were prepared and tested. The engine was a FIAT M724, installed in a Alfa Romeo 156 1.9 JTD, with a Bosch common-rail injection system (EDC-15C). At the exhaust of the engine, soot, NO\dx, HC, CO, and CO\d2 were measured. The experiments represent the potential of diesel reformulation technology with synthetic fuels coupled with the new diesel technology generation.

The need for special lubricants to meet the particular requirements of the australasian vehicle population, has already been raised within the SAE. This paper discusses possible future automotive engine oil requirements which could be required to meet the anticipated trends in vehicle registration patterns in Australia and New Zealand. In projecting future needs, the effects of fuel quality and availability, possible alternative fuels, and changes in environmental legislation are also considered. Although the requirements of 'off highway' mining and earthmoving equipment need to be taken into account in setting targets for lubricating oil performance, no attempt has been made in this paper to analyse the sales of this type of equipment (a).

B.C. Hydro is concerned about the long term storage stability of middle distillate fuels. In the first half of 1982 an extensive literature survey was initiated and various experimental approaches were evaluated. Our laboratory followed other investigators in the field. Fuel quality after aging for 12 weeks at 110/sup 0/F was selected as an accelerated test for the assessment of fuel storage life. Thermal aging for 16 hours at 212/sup 0/F was adopted for fast fuel screening, and the more severe conditions of 212/sup 0/F for 60 to 120 hours for the testing of highly stable fuels and additives. A total of seven test fuels were tested under various conditions. Eight fuel additives were tested, and of these - three additives (so called combination additives) were found to be most effective in controlling thermal aging of (''Keogh'') fuel. Initial results of ultrasound aided thermal aging at 110/sup 0/F seem to indicate that the so called ''induction period'' is accompanied by poor aging statistics.

As vehicle design and fuel quality trends continue to move into a regime where driveability malfunctions become exacerbated, hot and cold weather and intake system icing test procedures are being developed under the auspices of the Coordination European Council to evaluate those aspects of driveability performance of common interest to both motor and oil industries in Europe. Following extensive road and dynamometer trials, development of the hot weather procedure is nearing completion and a draft cold weather test method has been prepared in readiness for road proving trials. The intake system icing procedure has yet to be studied. Reference fuel properties have been nominated for each of the three aspects of performance. 7 refs.

This paper describes a new design of electrical fuel pumps for fuel injection systems. As fuel quality changed considerably in the last years, hot-fuel handling of pumps became insufficient and had to be improved. This was being achieved by connecting a hydro-dynamic pre-stage in series with the main pump unit which is of positive displacement type. Modern cars are highly sophisticated in engine noise reduction. Noise caused by pressure pulsation and body vibration of fuel pumps, having been concealed formerly in the total sound level, is audible now and has to be reduced. Solutions which have been put into practice will be shown and test results obtained on test bench and in cars are given in this paper.

Increasing recognition of the constraints imposed by limited petroleum supplies, rising costs, and governmental regulations will result in efforts to maximize the efficient use of petroleum liquids as transportation fuels. These efforts will include optimization of the petroleum product mix, broadening of fuel specifications, greater use of fuel additives to provide acceptable fuel quality, and new lubricants including new chemical additives to improve overall vehicle fuel economy. Beyond 1990, synthetic fuels and advanced lubricants formulations will begin to make their contribution.

To develop empirical road octane number (RdON) equations and to obtain the relationship between high speed RdON and fuel quality, RdON were determined by the Modified Uniontown Technique (MUT) and the Modified Boraderline Technique (MBL) using 1974 and 1975 Japanese passenger cars. The effects of RON and DON on RdON on RdON-MUT were more pronounced than that of MON. Aromatic and olefin hydrocarbon types had little influence on RdON-MUT. RdON-MBL measured at low speed was similar to RdON-MUT. As speed increased however, it was influenced by MON. Road octane number depreciation (delta RdON) at high speed was increased with sensitivity or olefin content. /SASI/