Measurement and Evaluation of the Performance Properties of Selected Locally Produced Lubricants (Engine Oil)

The performance of the oils selected in this work was tested for considering Viscosity, Viscosity Index, Density, Flash Point, Pour Point, and Carbon Residue. The most important of all the properties which makes the oil protect against wear is viscosity that helps to reduce friction between moving parts in the engine. The Viscosities of the oils; Oando SAE 20W50, Total SAE 20W50, Mobil 1 SAE 0W40, Total SAE 40, and AZ SAE 20W50 at 24.8°C (room temperature) and 100°C (maximum test temperature) are 290 cSt and 18 cSt, 290.5 cSt and 20 cSt, 286.4 cSt and 21.20 cSt, 295.2 cSt and 15.60 cSt, 296.8 cSt and 19.60 cSt respectively. This implies that the Mobil 1 is most preferred as it has the least change in viscosity with respect to change in temperature and Total SAE40, a monograde oil as the least preferred as it has highest change in viscosity with respect to change in temperature when high temperature is expected in the service environment. The pour points of the oils are -240C, -22 0C, -280C, -150C, and -220C respectively.

Based on this, all the oils are suitable for use in internal combustion engine in Nigeria and Africa. However, in an environment where very low temperature is expected during winter, the Mobil 1 (synthetic Oil) is most preferred and the monograde Oil is not suitable as the flowability may not be good enough at engine start up. The flash point of the Oils is 175 0C, 160 0C, 160 0C, 102 0C, and 170 0C respectively. These Oils are suitable for use in internal combustion engine as all the flash points are above the expected temperatures (0C) during a normal working condition. The carbon residue found in the Oils was 0.95 %, 0.90 %, 0.60 %, 1.00 %, and 0.95 % respectively. The Synthetic Oil has the lowest carbon residue and the monagrade Oil has the highest carbon residue, and so the synthetic Oil is most preferred based on carbon residue result since high amount of carbon residue is a disadvantage. In all the results of laboratory test, all the Oils were seen to be suitable in internal combustion engine with the most preferred Oil as the synthetic followed by the multigrade and the least performing oil is the monograde.

To carry out Pressure Mapping Experiment in this work, a pressure mapping equipment was developed. An Internal Combustion Engine, Thermocouple, Tachometer and Pressure Tube were obtained from the market and integrate together to function as desired based on theoretical background of pressure mapping. The pressure mapping experiment is a fast method of measuring the performance of the lubricating Oil by mapping the pressure of the Oils in an internal combustion engine. This Oil pressure mapping is recommended for the evaluation of the performance properties of the Oils in our local market.