1997 Buick Regal Owner's Manual - Page 374

I Long Trip/Highway Maintenance Schedule 45,000 Miles (75 000 km) 0Change engine oil and filter (or every 12 months, whichever occurs first). An Emission Control Service. (See footnote * .) 0Replace passenger compartment air filter. 0Rotate tires. See "Tire Inspection and Rotation" in the Index for proper rotation pattern and additional information. (See footnote +.) 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 90O F (32°C) or higher. - In hilly or mountainous terrain. - When doing frequent trailer towing. - Uses such as found in taxi, police or delivery service. I f you do not use your vehicle under anyof these conditions, the fluid and filter donot require changing. I DATE ACTUAL MILEAGE SERVICED BY: 7-32