This research was focused on the problem of lubrication of the TIGER engine in the Mbujimayi city, which causes harmful problems on this type of engine and which has an impact on the socio-economic life of Mbujimayi’s population. For that we tried to know the causes of the lack or the bad lubrication in the TIGER engine in order to propose some solutions to guarantee the long life of the engine. The results obtained showed that a large part of the people interviewed, 83%, do not know why oil-gasoline should be mixed at the time of purchase and 17% have limited knowledge of this mixture. At the end of this study, it also emerged that 40% of the breakdowns that occur on the TIGER engine are wear and tear and is caused to 71.4% by the lack or poor lubrication.

Lubricating oils are essential to ensure the proper functioning of an engine. They are composed of base oils of petroleum or synthetic origin and additives. The latter confer good properties to lubricating oils. However, these characteristics can be lost after use. The lubricating oils of the engine type become black during its use, and this is due to their degradation because of several phenomena, such as oxidation, contamination, as well as corrosion and other phenomena. The results obtained showed well, that this engine oil degrades quickly, and also remarkable with the change of color that becomes more and more black, contains solid contaminants that can be the cause of engine damage. In addition, of the mills in the Dibindi market, 94% are equipped with single-cylinder diesel engines. Of these 94%, only 29% of the mills reuse the used oil, and 48% of the users do so because of lack of financial means, and 43% prefer to earn a lot of money by reducing the expenses related to the purchase of new oil. 49% do not know the negative consequences that would happen if they reuse used oil; and finally, in the single-cylinder diesel engines targeted, 25% of the breakdowns are due to bad lubrication or bad lubricants.