The 2013 Scion xD looks as if it should get excellent fuel economy. In the grand scheme, it does--but it's still a few miles per gallon behind some much larger cars, and well off the gas-mileage marks set by the best subcompacts.
Granted, its gas-mileage ratings are roughly on par with other tall, boxy hatchbacks like the Kia Soul or Nissan Cube, but the xD's numbers just don't meet expectations, whether they're examined in the city or on the highway, with a manual transmission or with the automatic. The xD's EPA ratings of 27 mpg city, 33 highway aren't much better, if at all, than most mid-size cars.
Why are the numbers so low? The xD's engine is somewhat larger than other small cars its size, and the higher, less aerodynamic stance probably doesn't help.