Investigation of the Extent of Wear Metals in Five Different Lubricating Oils Before and After Exposure to Engine Stress

Abstract

Five different brands of Lubricating oils were used in five different vehicles viz: Toyota Carina II, Toyota 1992 (First lady), Golf 1990 Model, Honda 1996 Model and Mercedes Benz 190 Model respectively. The Ash method was adopted for digestion of samples followed by dissolution of samples with 5cm3 of 0.1M HCl acid, the digested samples was subjected to Atomic Absorption Spectroscopy. A selected wear metal concentrations determined for fresh lubricating oil, has a mean value between 0.36 to 5.86 for Al, 0.46 to 7.87 for Cr, 0.256 to 0.913 for Cd, 1.337 to 4.033 for Cu, 4.04 to 31 for Pb, 0.75 to 3.2 for Fe and 0.76 to 36.4 mg/kg for Mn. While their used oil wear metal concentration were in the range of 8.83 to 16.833 for Al, 7.03 to 45.5 for Cr, 1.64 to 22.0 for Cd, 3.35 to 16.27 for Cu, 27.8 to 151.3 for Pb, 3.707 to 9.73 for Fe and 13.07 to 45.10 mg/kg for Mn. For the same wear metals. However the highest concentration of wear metal, was observed in Honda (1996 Model) while the information about wear metals concentration will be helpful in monitoring and maintaining vehicles engine