What kind of oil does a cadillac cts 2003 take?

The kind of oil the Cadillac CTS 2003 takes iS5W-30. Your oil needs to be changed eventually. Every 5,000 to 10,000 miles is a good rule of thumb. If You don't change it, there will be problems with the engine. Having high quality oil is key for the engine to run smoothly. You will run into issues with the oil at some point. A common problem is an awful burning smell. This needs to be inspected as soon as possible or the car might explode. Bad oil can cause the engine to stop working. You could experience terrible gas mileage. Knocking noise may come about from the engine.