STUDIES OF SOME ENGINE OILS MANUFACTURED IN NIGERIA

Abstract

Nigeria blending plants were few and mostly dominated by the multinationals. Lubricants produced in the past were of high quality but expensive. With time the lubricant market boomed and more investors entered the operations leading to quality challenges and adulterated products began to litter the market with some manufacturers’ addresses becoming elusive. In the present work some physical and chemical properties of selected multi- and mono-grade lubricants manufactured in Nigeria have been investigated. The values of viscosity in this investigation were found to decrease gradually with temperature for both multigrade and monograde lubricants.  For most lubricants a high flash point is desirable to prevent ignition in a motor. Mobil super (20W50), Conoil (20W50) and Total (SAE40) were found to have high flash points, while Oando SMOR (SAE40), Texaco Havoline (20W50) and AP Super V (20W50) have low flash points. The general specification for density of petroleum lubricants is 0.85-0.95. This investigation has confirmed that Nigerian manufactured lubricants are of good quality with densities above 0.85. The deposition of the sludge increases the exhaust back pressure and reduces over time the fuel economy. Verification of sludge formation is a guide to the formation of carbon deposits of lubricating oil in the cylinders of internal combustion engines. In this test low values of carbon residues were obtained indicating very small sludge formation from the lubricants.  However Amasco (20W50) and Total (20W50) produced high carbon residues of 2.8800 and 1.5018 respectively. The Total Base Number (TBN) which is a measure of the reserve alkalinity of oil is another manipulated property and it is the lubricants acidity. The values from this work indicate satisfactory ability of the lubricants to neutralize any acid formed during operation and minimize oxidation. The trace element is a measure of the additives in the lubricant and their functions include keeping the engine clean, extension of the range of applicability and useful life of the lubricant. Na, K and Ca which serve these functions are found in appreciable quantities in this investigation.  The hydrogen content of oil indicates the level of contamination by other lipids and the parity with lubricants processed elsewhere. The values ranged between 11.0 to 12.30 by weight percent and compares with the results of other investigators.