1997 Buick Century Owner's Manual - Page 345

I ShortTrip/CityMaintenanceSchedule I 50,000 Miles (83 000 km) 0Change automatic transaxle fluid and filter if the vehicle is mainly driven under one or more of these conditions: - In heavy city traffic where the outside temperature regularly reaches 90 O F (32O C) or higher. - In hilly or mountainous terrain. - When doing frequent trailer towing. - Uses such as found in taxi, police or delivery service. If you do not use your vehicle underany o these f conditions, the fluid and filter do not require changing. 48,000 Miles (80 000 km) 0Change engine oil and filter (or every 3 months, whichever occurs first). An Emission Control Service. 0Replace passenger compartment air filter. 0Rotate tires. See "Tire Inspection and Rotation" in the Index for proper rotation pattern and additional information. (See footnote +.) DATE ACTUAL MILEAGE SERVICED BY: DATE MILEAGE ACTUAL SERVICED BY: 7-15