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The aim of this research is to investigate the effects of ashless dispersant of lube oils on diesel exhaust particles. Emphasis is placed on particle size, morphology, nanostructure and graphitization degree. Three kinds of lube oils with different percentages of ashless dispersant were used in a two-cylinder diesel engine. Ashless dispersant (T154), which is widely used in petrochemical industry, were added into baseline oil at different blend percentages (4.0% and 8.0% by weight) to improve lubrication and cleaning performance. A high resolution Transmission Electron Microscope (HRTEM) and a Raman spectroscopy were employed to analyze and compare particle characteristics. According to the experiment results, primary particles diameter ranges from 3 nm to 65 nm, and the diameter distribution conformed to Gaussian distribution. When the ashless dispersant was used, the primary particles diameter decrease obviously at both 1600 rpm and 2200 rpm.

In this study, the effect of volatile fractions from engine lubricating oil on diesel particle emissions were studied experimentally. One commercial CF lubricating oil was used and distilled to subtract the different volatile fractions with boiling temperature of 220 °C, 260 °C and 300 °C, respectively. Oils derived from this distillation process were applied as the lubricating oil and following engine experiments were conducted. Diesel primary particles were sampled with a costume designed thermophoretic system. A fast response particulate spectrum equipment was employed to study the size distribution and number concentration of particles in the exhaust. Transmission electron microscopy was used to characterize the size distribution of the primary diesel particles relates to different oil volatile fractions.

Catalyzed gasoline particulate filter (cGPF) is the prime technology to meet future stringent regulations for particulates from gasoline direct injection (GDI) engines. One of the technical concerns is the ultimate durability of cGPF in regards to engine lubricant formulations. This study investigated two tailored lubricant formulations on catalyzed GPFs which were aged on engine followed by emission testing on vehicle. An engine accelerated aging protocol was developed for cGPFs to simulate thermal aging, ash and soot loading that is at least equivalent to 200,000 km durability requirement. Evaluations include tailpipe emission levels, backpressure, catalytic performance, and post-mortem analysis. Both formulations have demonstrated a high level of cGPF performance retention; performance being assessed in terms of emission level at the end of durability demonstration testing. These formulations provide flexibility in selecting robust lubricant to meet various system requirements.