1999 GMC Sonoma Owner's Manual - Page 313

yellowblue Scheduled Maintenance Short Trip/City Definition Follow the Short Trip/City Scheduled Maintenance if any one of these conditions is true for your vehicle: Short Trip/City Intervals Every 3,000 Miles (5 000 km): Engine Oil and Filter Change (or 3 months, whichever occurs first). Chassis Lubrication (or 3 months, whichever occurs first). Drive Axle Service (or 3 months, whichever occurs first). Every 6,000 Miles (10 000 km): Tire Rotation. Every 15,000 Miles (25 000 km): Air Cleaner Filter Inspection, if driving in dusty conditions. Front Wheel Bearing Repack (2WD only) (or at each brake relining, whichever occurs first). Automatic Transmission Service (severe conditions only). Every 30,000 Miles (50 000 km): Air Cleaner Filter Replacement. Fuel Filter Replacement. Every 50,000 Miles (83 000 km): Automatic Transmission Service (normal conditions). Every 60,000 Miles (100 000 km): Engine Accessory Drive Belt Inspection. Fuel Tank, Cap and Lines Inspection. D Most trips are less than 5 to 10 miles (8 to 16 km). This is particularly important when outside temperatures are below freezing. D Most trips include extensive idling (such as frequent driving in stop-and-go traffic). D You operate your vehicle in dusty areas or off-road frequently. D You frequently tow a trailer. D If the vehicle is used for delivery service, police, taxi or other commercial application. One of the reasons you should follow this schedule if you operate your vehicle under any of these conditions is that these conditions cause engine oil to break down sooner. 7-5