1999 Chevrolet S10 Pickup Owner's Manual - Page 347

yellowblue Long Trip/Highway Scheduled Maintenance under one or 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 found in taxi, police or delivery service. If you do not use your vehicle under any of these conditions, change the fluid and filter every 50,000 miles (83 000 km). j Replace fuel filter. An Emission Control Service. (See footnote[.) j Replace air cleaner filter. An Emission Control Service. j Rotate tires. See "Tire Inspection and Rotation" in the Index for proper rotation pattern and additional information. (See footnote +.) j Change automatic transmission fluid and filter if the vehicle is mainly driven 7-39