According to 2007 Chevrolet Owner’s Manual, SAE 5W-30 is best for your vehicle.
If you are in an area of extreme cold, where the temperature falls below −20°F (−29°C), it is recommended that you use either an SAE 5W-30 synthetic oil or an SAE 0W-30 oil. Both will provide easier cold starting and better protection for the engine at extremely low temperatures.
Do not add anything to the oil. The recommended oils with the starburst symbol that meet GM Standard GM6094M are all you will need for good performance and engine protection.
When to Change Engine Oi?
If any one of these is true for you, use the short trip/city 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 use a carrier on top of your vehicle.
The vehicle is used for delivery service, police, taxi, or other commercial application.