I'm guesing that the PT does worse in just about every mileage catagory than similar cars. Then again, it's solid, rides right, and looks right.
Only the HHR comes close. It's heavy too, and mpgs aren't any better. I have a buddy that had one. His wife used it for groceries and kiddy rides to the daycare before she went off to work. They replaced it with a Taurus X, the wagon like cross-over now out of production. The Ford with V-6, and 8 seats gets better mpg. Go figure.
We love our PT, and recommend it to anyone that wants a small good looking car. But if you want mpg, buy a Focus (or dare I say it?) Cobalt. Chrysler isn't going to get you mpgs...