Abstract
Present research work deals with refining of car engine used lubricating oil into base oil by solvent extraction?using hexane and ethyl acetate. The extracted oil was further diluted by making various solvents to extract oil ratios, to determine the physiochemical parameters such as acid values, viscosity, specific gravity and refractive index. Percent sludge removal (PSR) and percent oil loss (POL) was calculated for determining the performance of the extraction process and quality of re-refined oil. Fourier Transform InfraRed (FTIR) analysis has also been done to study the changes in used and unused car engine lubricating oil.