When to Change Engine Oil

WHEN TO CHANGE ENGINE OIL (WITHOUT THE GM OIL LIFE SYSTEM)
If any one of these is true for you, use the severe maintenance schedule:
- Most trips are less than 5 miles (8 km). This is particularly important when outside temperatures are below freezing.
- Most trips include extensive idling (such as frequent driving in stop-and-go traffic).
- You frequently tow a trailer or use a carrier on top of your vehicle.
- 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.
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 will cause engine oil to break down slower.