2001 Chevrolet Blazer Owner's Manual - Page 321

Engine Oil Additives Don't add anything to your oil. The recommended oils with the starburst symbol are all you will need for good performance and engine protection. 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. If none of them is true, use the long trip/highway maintenance schedule. Change the oil and filter every 7,500 miles (12 500 km) or 12 months -- whichever occurs first. Driving a vehicle with a fully warmed engine under highway conditions causes engine oil to break down slower. When to Change Engine Oil If any one of these is true for you, use the short trip/city maintenance schedule: 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 or use a carrier on top of your vehicle. D The vehicle is used for delivery service, police, taxi or other commercial application. 6-14