Abstract: The effect of lubricating oil parameters on the constituent of particle emitted from diesel engine was investigated on a turbo charged diesel engine with four kinds of specially formulated lubricating oils. The effect of base oil type and quantity of ash content on the oxidation activity, metallic element and paraffin of particle emitted was studied. This study focuses on the original particle emission of diesel engine, and has reference value of the regeneration of diesel particle filter. The results show that base oil has little impact on oxidation activity of particle at low engine load when oxidation is more active. And high engine load leads to lower oxidation activity of particle. The emitted particle has a higher oxidation activity when poly alpha olefin (PAO) lubricants as well as lubricants of lower ash content are used. A smaller quantity of metallic elements is found in emitted particle when tested lubricants has the similar base oil but lower ash content. Compared with ordinary mineral oil, ordinary PAO shows more metallic element emission in particle, but the difference is not as obvious when PAO and mineral oil of low ash content is used. It can be concluded that high load of engine leads to more paraffin emission in particle, and when PAO lubricants are used, less paraffin is emitted. Low ash content leads to less paraffin emission.

Key words: lubricating oil; diesel engine; base oil; ash content; particle emission