Engine oil is more than just a lubricant; it is the lifeblood of your vehicle. It is stored in the oil pan (holding between 3.5L and 7L depending on your car) and is constantly circulated by the oil pump to keep internal metal components from grinding against each other. As it moves, it also helps cool the engine and cleans out microscopic debris, which is then trapped by the oil filter. In the heat of South Africa, oil viscosity is crucial. If the level drops too low, the remaining oil overheats and thins out, leading to friction that can literally "weld" your engine into a solid block of metal in minutes.
Loss of engine oil is almost always a sign of a serious underlying problem. Unlike fuel, oil is not "consumed" in a perfectly healthy engine; it is meant to stay in the system. Ignoring a low oil level is a gamble with your car's life. Modern synthetic oils are designed to last between 7,500km and 15,000km, but they cannot protect an engine that is running dry.