I would think the Zetec should do better then a Duratec. On my last trip to Pittsburgh (400 Miles on one tank) I got 32.5 MPG. (402 miles on 12.3 Gallons), V6 ATX. And I was not driving for best mileage, though it seems I get better MPG when I drive ummm, quickly?, then if I drive ummmm,"slowly", if you get my drift.
Over the last 8000 miles of mixed driving I have 25 MPG. (I keep of spreadsheet of all expenses as I use the car for work.)
Hope the O2 asensor replacement does the trick.
