I have an '05 Escape XLS 4cyl, 5-speed and I have gotten as high as 38mpg on the highway and I have been averaging around 32 to 34mpg in normal everyday driving conditions including stop and go traffic...I would think that the automatic transmision may drop those results by 1 or 2 mpg.
P.S...Love my Escape and the 4 cyl has plenty of power too, 155 hp...
Good Luck!