I don't know about the new cars, but they used to say that up to 1 quart per 1,000 miles was acceptable. Seems a bit high!
You may have a leak and don't realize it - many leaks only manifest themselves while driving when the system is at pressure. Also a common area for Duratec leaks is at the oil pan. That's where mine drips. I loose about .25 quarts after about 6 to 7,000 miles.
