​​Why should we change Engine Oil of a Vehicle regularly?

There are a lot of different components to an engine and a lot of them need to be properly lubricated when the engine is running. This is where engine oil comes into play.
Over time, your engine oil will begin to collect contaminants and while your oil filter will catch most of this, the oil can still remain contaminated. This results in the engine oil not being as effective, which can cause problems throughout your engine.
Rub your hands together. You’ll notice that your palms begin to get hot, this is due to friction. Now, if you add a few drops of oil (or hand wash) to your hands and do the same thing, less heat will be generated as friction is reduced. Following on from this, place some salt in the palms of your hand. Notice how even though your “oil” is still on your hands, friction is still being created. This is similar to how dirty oil reacts in a running engine.