Ford recommends getting your 2018 Ford Focus oil & filter replaced every 3,000-5,000 miles for conventional oil.
Synthetic oil usually should be replaced every 7,500 - 10,000 miles.
Keep in mind it's best to check your owner's manual and with your dealer to find out the intervals that work best for your vehicle.
Capacity: With filter 5.7 quarts.
After refill check oil level.