The Ford oil filter does more to help protect your engine from premature wear than any other component on your vehicle. This might be just a simple canister with a paper element that the oil passes through, but the particulates the oil filter removes from the engine oil would be responsible for an excess of unwanted friction applied to the bearings and other internal engine components. The periodical changing of the oil filter on your Ford was determined to be recommended at 3,000 to 5,000 miles because this is when the paper element in the filter would become saturated with the particulates the engine was producing. These particulates are the carbon particles that are a byproduct of burning the fuel in the combustion chamber as well as very tiny metallic shavings and dust from your internals. The oil itself has not gone bad, just highly contaminated and why it should be replaced. Once past the 5,000 mile mark the Ford oil filter will start to clog up. The flow of oil through it begins to become impaired, and the check value in the oil filter will close. This is a safety feature on your Ford that will permit oil to continue to flow, even though it is dirty with contaminates. Dirty oil is better than none or a reduced amount of oil on the moving parts in your Ford engine. It is true that with the aid of a centrifuge, contaminates in the oil can be removed and the oil reused for other purposes other than engine oil. The oil filter is a disposable part that has no practical purpose once the paper element is filled with carbon contaminants. It must be properly disposed of because it is considered a hazardous waste product.