Do you really need to replace your oil filter every time the oil is changed? Well, that depends. This is certainly a much debated topic. But before jumping into this, let's take at the oil itself and see the effect it has on engine function.
The oil filter does exactly as it's name implies, it filters the oil in your vehicle. The engine's oil pump pushes the oil into the filter. Contaminants are caught by the oil filter before it circulates back through the engine. Without filtration, the oil would become saturated with hard, tiny particles that can wear out the oil pump's components and damage the bearing surfaces of an engine.