Over time, engine oil not only loses its ability to lubricate or viscosity, but it also accumulates acids and other combustion byproducts.    These compounds are harmful to gaskets, seals, bearings, and other metal surfaces. Even if the lubricating quality of oils keeps improving, the materials in suspension damage the internal engine parts.   Changing the oil and filter every six months or 3,000-5,000 miles is a form of preventative and regular maintenance.   Whether you need a tune-up or oil change in West Chester, we are here to take care of all your auto repair needs.