1998 Pontiac Firebird Owner's Manual - Page 336

I Short TripKity Maintenance Schedule I I DATE 30,000 Miles (50 000 km) 0 Change engine oil andfilter (or every3 months, whichever occurs first). An Emission Control Service. 0 Change the rear axle lubricant if vehicle is used to pull a trailer, gear 0 Replace air cleaner filter. An Emission Control Sewice. 0 Inspect fuel tank, and linesfor damage or leaks. Inspect fuel cap gasket cap for any damage. Replace parts as needed. An Emission ControlService. (See footnote?.) 0 Change automatic transmission fluid and filter if the vehicle is mainly driven under oneor more of these conditions: - In heavy city traffic where the outside temperature regularly reaches 90°F (32°C) or higher. - In hilly or mountainous terrain. - When doing frequent trailer towing. - Uses such as foundin taxi, police or delivery service. If you do not use your vehicle under any of these conditions, change thefluid andfilter every 50,000 m l s (83 000 km). ie C Rotate tires, See "Tire Inspection and Rotation" in the Index for proper l rotation pattern and additional information. footnote +.) (See 7-11