According to the owner's manual, Ford recommends using Motorcraft brand oil. It does not specify a specific oil weight. Commonly, people put 5W-20 oil into their engines when the car is relatively new. After the car passes the high-mileage point, which is usually in the range of 75-100,000 miles, oil change technicians will begin recommending the 5W-30, frequently branded for high-mileage engines.