"Is higher mileage motor oil worth the extra cost? Do gasoline additives really clean fuel lines and fuel injectors?"

"Good question. High mileage motor oil contains special additives to help revitalize engine seals and restore piston ring seal, however, once you start, you have to continue using the high-mileage product to produce any gains. Gasoline additives can help keep your injectors and lines clean, but generally contain a relatively low concentration of these additives. It is still recommended to have your fuel injectors serviced by your automotive service provider as warranted."