where did the oil go?

Thanks for all the replies and opinions. I have about 5-600 miles to go before changing oil again and am trying to decide whether to stay with the 5-20 synthetic blend the Ford dealer uses or go back to the 5-20 regular oil I was using before. I am leaning towards sticking with the synthetic blend. In answer to comments, the owners manual says to use 5-20 motorcraft or equiv. oil, does not specify synthetic blend but the oil container pictured in the book clearly says synthetic blend. They also state to not use any oil additives. Thanks for the replies.