I use 15/40 Motorcraft with a Motorcraft filter. You can get both fairly cheap at Walmart. I think the filter number is an FL-2016, and 15 quarts of oil. I always buy the Motorcraft 5Qt. jugs, makes it a no-brainer, you'll need 3 of them. While your under your truck, drain the water separater. Look in your manual, I'm not 100% sure on the filter number.