1998 Ford Expedition Owner Guide 1st Printing - Page 156

Maintenance and care Do not use supplemental engine oil additives, oil treatments or engine treatments. They are unnecessary and could, under certain conditions, lead to engine damage which is not covered by your warranty. Changing the engine oil and filter Change your engine oil and filter according to the following mileage and time requirements, whichever occurs first: • Normal Schedule - 8,000 km (5,000 miles) or six months. • Severe Duty Schedule - 5,000 km (3,000 miles) or three months. Severe duty operation would include extensive idling, trailer towing, driving in severe dust and police, taxi or delivery service. Ford production and aftermarket (Motorcraft) oil filters are designed for added engine protection and long life. If a replacement oil filter is used that does not meet Ford material and design specifications, startup engine noises or knock may be experienced. It is recommended you use the appropriate Motorcraft oil filter (or another brand meeting Ford specifications) for your engine application. 156