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New environmental regulations and stringent emissions standards have lowered the limits for Particulate Matter (PM) mass and Particle Number (PN) emissions requiring further optimization of gasoline direct injection (GDI) engines. Partially burned and unburned lubricating oil contributes significantly to black carbon and soot particle emissions which are not neglectable compared to fuel generated particles. Oil emissions are influenced by engine speed and load conditions but also by engine oil properties and formulation. Minimizing oil consumption has become a fundamental concern and there is a real need for better understanding associated sources and mechanisms. Therefore, researchers and engineers need appropriate tools and methodologies to solve these new problems. A reliable oil consumption measurement methodology able to quantify oil emissions (all oil emissions forms) and only oil emissions is a prerequisite.

In order to meet the particulate emission targets (6 x 1011 #/km), some gasoline direct injection (GDI) engines might require the use of particulate filters (GPF). The lifetime of wall-flow filters is influenced by the composition of the engine lubricant due to its potential to contribute to the ash accumulation in the GPF. Due to space constraints and to facilitate trapping and soot regeneration, a large number of GPFs will be in closed-coupled configuration. A study was carried out on an endurance test with a radio labelling method and conventional mass gain measurement to evaluate this GPF configuration, and verify the impact of metallic additives contained in the lubricant such as magnesium (Mg) and calcium (Ca) based detergent, a zinc (Zn) based anti-wear, and a molybdenum (Mo) based friction modifier. Two oils were evaluated, with two levels (0.85%-1.1%) of SAPS (Sulphated Ash, Phosphorus and Sulphur).

In order to meet the EU6c, 6×1011 # / km particulate number emission target that will be introduced in 2017, some gasoline direct injection (GDI) engines might require the use of particulate filters (GPF). The lifetime of wall-flow filters is influenced by the composition of the engine lubricant due to the potential of the lubricant to contribute to ash accumulation in the GPF. In order to anticipate the potential need for new, lower ash lubricants, an endurance test was performed using a commercially available GPF. A radio-labelling method was used to identify the amount of lubricant derived ash trapped in the GPF in addition to conventional weighing measurements. After the endurance test, during which 9 kg of 1.17% sulphated ash oil was consumed, approximately 50 g of ash had accumulated in the GPF. This amount is only 48% of the expected amount based on fresh oil sulphated ash concentration and oil consumption.

New environmental regulations require significant reduction of fuel consumption and engine emissions. This implies improvement of the internal combustion (I.C.) process, reduction of friction, development of complex after-treatment systems, and a reduction of oil consumption. New technical challenges are related to fuel dilution problems in diesel and super-ethanol engines; new wear problems are due to fuel dilution and soot loading in the lubricant; clogging and poisoning problems of after-treatment systems are related to oil consumption, etc. Therefore, researchers and engineers need appropriate tools to better understand and solve these new problems. The paper focuses on the combination of modern engine test beds equipped with innovative radionuclide techniques for real-time oil consumption, oil aeration, fuel dilution, and for on-line wear measurement.

The lifetime of the new technologies of after-treatment devices is influenced by the composition of engine oil, making it necessary to study the compatibility of lubricants with these devices. These compatibility tests usually evaluate parameters such as the long-term performance of after-treatment systems, the quantity and nature of accumulated residues due to the lubricant used, back-pressure increase, etc. This paper presents a novel, non-destructive radionuclide technique based on labeling the different elements in the engine oil (e.g. zinc and calcium), that provides additional information to after-treatment system compatibility tests: on-line measurement in the after-treatment device of the accumulation of elements from oil additives, and visualization of their distribution inside the device (inlet/outlet). Most of the work presented here focuses on the accumulation of zinc and calcium from the lubricant in a Diesel Particulate Filter (DPF).