|Oil lubricates engine parts. It also carries heat away from parts that build up an incredible amount of friction, enabling your engine to withstand more extreme heat than without it. An oil filter removes impurities from the oil that is coursing through your engine, improving overall performance. Oil becomes full of particles at a certain point, regardless of how premium your filter is, which means it is sending more impurities to your engine each time it cycles through. For normal driving, a change every 7,500 miles is sufficient. If you live in an extreme climate, are a stop-and-go driver or pull a trailer, a change every 3,750 miles is recommended.