Another 5w-20 Motorcraft oil and 820S Motorcraft filter user here. I buy the 5 qt jugs only. You save money over buying single quarts, and if you buy two now, then you only have to buy one the next couple times and you always have a little on the shelf in case you need to add a bit between changes. Also, my truck uses about 3/4 of a quart between changes (5K miles) so I check at every fill up without exception. It only takes a second and since I fill up once a week, it helps me monitor any unusual consumption.