1997 Buick Century Owner's Manual - Page 339

I Short TripKity Maintenance Schedule I 15,000 Miles (25 000 kmj 0Change engine oil and filter (or every 3 months, whichever occursfirst). An Emission ControlService. 12,000 Miles (20 000 kmj 0Change engine oil and filter (or every 3 months, whichever occurs first). An Emission Control Service. I7 Replace passenger compartment air filter. 0Inspect air cleaner filter if you are driving in dusty conditions. Replacefilter if necessary. An Emission ControlService. (See footnote?.) 0Rotate tires. See "Tire Inspection and Rotation" in the Index for proper rotation pattern and additional information. (See footnote +.) I I I ACTUAL MILEAGE DATE SERVICED BY: DATE ACTUAL MILEAGE SERVICED BY: 7-9