Before you begin
The Cadillac Northstar V8 is widely known to consume more oil than most engines—as much as a quart every 1,000 miles. Though you may be adding new oil fairly frequently, it's important that you still change your engine oil and filter every 3,000-5,000 miles, depending on your driving conditions. Cadillac (as well as many automotive experts) strongly discourage the use of any oil additives, even those that claim to decrease oil consumption.