I've been having all my service done by a dealer using Motorcraft oil. I need to add oil in the morning and the dealer is closed till Monday. What commercially available engine oil is equivalent and compatible with the Motorcraft oil the dealer uses?
When you switch brands of oil, you leave apprx. 3-4 quarts of the old oil in the system, so you are mixing oils at that point. Lots of people do it (switch oils that is)! As Mike said - any properly rated diesel oil will work.