The mileage thing, yes that's as good as I get, too.
The tank capacity thing, I have been suspicious of mine for a while too, but my suspicion is a result of my needle being on or near E and no low gas light coming on. I should just keep going until I run out sometime and see how many gallons go in.
edit: oops, apples and oranges to a degree. My turbo swallows a lot of gas, maybe others with something more like your car will have different numbers. At least our cars are similar age-wise.