Getting the oil in your car changed regularly is a big deal? The oil lubricates all the parts of the engine that makes your car run.Over time the oil gets dirty. New oil is a light yellow color and very runny; over time the oil thickens and changes to a darker color. At this point it can start to damage the engine instead of keeping things running smoothly. Changing the oil and replacing the oil filter every 3000 to 5000 miles will keep your engine running smoothly and last longer. It will also give you better gas mileage, and who doesn't want that?