1995 Buick Century Owner's Manual - Page 272

I MaintenanceSchedule I I 33,000 Miles (55 000 km) C Change engine oil and filter (or every I 3 months, whichever occurs first). An Emission Control!Service. 30,000 Miles (50 000 knz) (Continued) Rotate tires. See "Tire Inspection and Rotation" in the Index for proper rotation pattern and additional information. DATE ACTUAL MILEAGE SERVICED B Y DATE ACTUAL MILEAGE SERVICED B Y 7-12