I haven't really had a chance to see what my '07 V-8 2WD gets in MPG since I work just 5 miles from where I live and I don't have to drive the freeways.
So, "In Town", I'm getting about 14/15 mpg's and about a month ago, I took a trip (aprox 300 miles) and was getting around 20 mpg's on the freeway with A/C on and 4 adults on-board.
My ST is "pure" stock with no mods.