1998 GMC Sonoma Owner's Manual - Page 264

As shown in the chart, SAE 5W-30 is best for your vehicle. However, you can use SAE low-30 if it's going numbers on an oil to be 0°F (-1 8°C) or above. These container show its viscosity, or thickness. Do not use other viscosity oils, such as SAE 20W-50. Engine Oil Additives Don't add anything to your oil. Your dealer is ready to advise if you think something should be added. When to Change Engine Oil If any one of these is true for you, use the short triplcity maintenance schedule: e Most trips are less than 5 to 10 miles (8 to 16 km). This is particularly important when outside temperatures are below freezing. a Most trips include extensive idling (such as frequent NOTICE: Use only engineoil with the American Petroleum Institute CertifiedFor Gasoline Engines "Starburst" symbol. Failure to use the recommended oil can result inengine damage not covered by your warranty. GM Goodwrench@oil meets all the requirements for your vehicle. If you are in an area where the temperature falls below -20°F (-29"C), consider using either an SAE SW-30 synthetic oil or SAE OW-30 oil. Both will provide an easier cold starting and better protection for your engine at extremely low temperatures. driving in stop-and-go traffic). a You operate your vehicle in dusty areas or off-road frequently. e You frequently tow a trailer. 0 The vehicle is used for delivery service, police, taxi or other commercial application. Driving under these conditions causes engine oil to break down sooner. If any one of these is true for your vehicle, then you need to change your oil and filter every 3,000 miles ( 5 000 km) or 3 months -- whichever occurs first. 6-14