Someone correct me if i'm wrong, but the epa instituted a stricter standard for measuring city/hwy mileage. As a result newer cars, although unchanged from previous years, report lower mileage figures.
Everyone "played the game" - Basically all auto mfg's made the numbers look better, for example the highway figure was calculated at a constant 50mph, smooth, level road, tailwind! that might be somewhat of an exaggeration (or not) but now the EPA has more stringent requirments to make the tests reflect more "real world" situations.
BTW, take a look at the change in Fords #'s vs. Foreign makes, the foreign cars took a BIG hit. I think the biggest hit was Toyota with its hybrid prius....
The other big problem is "city" driving is such a broad term and can mean so many different things. In true CITY driving (like driving in a physical city - Washington, DC), I get between 9-12 mpg depending on how many lights I hit and how many times I am first in line at the stoplight. If more rural "city" driving, where its just putting around town in the suburbs, I'll get 15-18 and even 20 on occasion. Thats also being able to drive 40-55 mph on most roads, with far fewer stops and starts.
Thanks for clearing that up. I'm back in the game and want to get a Mustang again. I would of made the mistake of considering a 2005 over a newer Mustang if I would'nt have asked!