Oil is a lubricant that keeps your vehicle functioning properly. Oil plays an essential role in the engine of your vehicle, where it helps alleviate friction between various moving components. Without the protective layer that oil provides, the heat created from friction would melt an engine’s parts together. As oil runs through your vehicle’s system, it also collects sludge, grime, and other contaminants that can harm the engine. In turn, the oil filter catches these contaminants and helps to prevent them from mixing with the oil. However, the filter can only hold so much. Over time, the small bits and miscellaneous muck will break down the filter’s defenses. When this happens, the result is dirty oil. In addition to being less effective overall, dirty oil can cause permanent damage to some parts of your vehicle. As such, oil and filter changes are considered an important part of vehicle maintenance.