1997 Buick Riviera Owner's Manual - Page 333

Short Trip/City Maintenance Schedule 44,000 Miles (110 000k t ) 0Change engine oiland filter (or every 3 months, whichever occurs first). An Emission Control Service. 49,000 Miles (115 000 km) 0Change engine oil and filter (or every 3 months, whichever occurs first). An Emission Control Service. 0Lubricate chassis co,mponents (or every 6 months, whichever occurs first). (See footnote#.) 0Rotate tires. See "Tire Inspection anu Rotation" in the Index for proper rotation pattern and additional information. +.) (See footnote DATE MILEAGE ACTUAL SERVICED BY, L