The malaysia engine oil in your car needs to be replace every few thousand miles for several reasons. As oil travels around the engine it is designed to pick up any loose scraps of metal that may have broken away and any other contaminants that may have entered the system. It them carries them away from the core of the engine, through the oil pan and to the oil filter. Here they are removed. Over time the oil becomes saturated with these microscopic fragments and chemical waste products and no longer has the capacity to absorb any more. At this point the contaminants will stay in the core of the engine causing damage such as wear and tear on the metal surfaces and the chemical waste can lead to a buildup of black sludge. This is one reason.
Another good reason to change your oil is the additives become depleted. Additives are included in the motor oil to change the way it behaves in cold and hot weather and also to clean the engine and prevent corrosion. Additives cannot be replaced separately to the oil. The only way to replace them is to replace the oil, they are an integral part of it. When it is time to change your oil you should also get a new filter. No use having clean oil circulating picking up debris if the oil filter is blocked. Incidentally, if the filter does become blocked a pressure valve is released at the oil continues to circulate. It is better to have dirty oil then no oil.
Changing your own malaysia engine oil is a very achievable goal even for novice mechanics. But you will need an oil filter wrench to remove the filter and either some ramps to let you lift the car safely so you can drain the oil pan or an oil extractor to suck the oil out of the sump. Your choice of motor oil is also important. Compromising with cheap oil change can be damaging to your engine in the long run. Better to spend a few more dollars now and save a few hundred, or even thousand, in the future.