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The focus of this study is investigation of the influence of fuel system pressure, intake tumble charge motion and injector seat specification - namely the static flow and the plume pattern - on the GDi engine particulate emissions under the homogenous combustion operation. The paper presents the spray characteristics and the single cylinder engine combustion data for the Delphi Multec® 14 GDi multi-hole fuel injector, capable of 40 [MPa] fuel system pressure. It provides results of a study of the influence of fuel pressure increase between 5 [MPa] to 40 [MPa], for three alternative seat designs, on the combustion characteristics, specifically the particulate and gaseous emissions and the fuel consumption. In conjunction with the fuel system pressure, the effect of enhanced charge motion on the combustion characteristics is investigated.

The progressive trend towards the GDi engine downsizing, the focus on better fuel efficiency and performance, and the regulatory requirements with respect to the combustion emissions have brought the focus of attention on strategies for improvement of in-cylinder mixture preparation and identification and elimination of the sources of combustion emissions, in particular the in-cylinder particulate formation. This paper discusses the fuel system components, injector dynamics, spray characteristics and the single cylinder engine combustion investigation of a 40 [MPa] capable conventional GDi inwardly-opening multi-hole fuel injection system. It provides results of a study of the influence of fuel system pressure increase between 5 [MPa] to 40 [MPa], in conjunction with the injector static flow and spray pattern, on the combustion characteristics, specifically the particulate and gaseous emissions and the fuel economy.

Particulate matter emissions are no longer only a concern in the development of Diesel engine powertrains. In addition to particulate mass requirements, the new European legislation for Euro 6 includes a proposed particulate number requirement for all vehicles with gasoline direct injection engines. Euro 6b will establish the first requirement in 2014 which will then be significantly reduced with the implementation of Euro 6c in 2017. This might coincide with the introduction of the World Light Duty Testing Procedure vehicle drive cycle test, raising the bar even higher to reach compliance to the particulate number legislative requirements. Several different investigations revealed that the particulate number emission will become very challenging while the limit for particulate mass can already be met with today's applications.

Since the introduction of the EURO 5 emission legislation particulate matter emissions are no longer only a concern in the development of Diesel engine powertrains. In addition to particulate mass (PM) requirements the new European legislation will also foresee the implementation of a particulate number (PN) requirement for all spark ignition (SI) vehicles with the introduction of EURO 6. Measurements with state of the art gasoline engine powered vehicles show that conventional MPFI engines are already below the future proposed limits while gasoline engines with direct injection are above these limits and will require additional development efforts. This paper discusses both fuel system component requirements as well as control strategies in support of reducing particulate emissions. On the component side, mixture formation in regard to evaporation rate and penetration is a key factor.

Proper lubrication of moving parts is a critical factor in internal combustion engine performance and longevity. Determination of ideal lubricant change intervals is a prerequisite to ensuring maximum engine efficiency and useful life. When oil change intervals are pushed too far, increased engine wear and even engine damage can result. On the other hand, premature oil changes are inconvenient, add to vehicle maintenance cost, and result in wasted natural resources. In order to determine the appropriate oil change interval, we have developed an oil condition sensor that measures the electrical properties of engine oil, and correlates these electrical properties to the physical and chemical properties of oil. This paper provides a brief background discussion of the oil degradation process, followed by a description of the sensor operational principles and the correlation of the sensor output with physical and chemical engine oil properties.