The short answer? You will have to drive this car in such a manner that it will piss off everyone around you to get the EPA estimated MPG in the city. The highway is never much of an issue for me, but I regularly see less than 25 in the city with my 6 speed NA V.
No, I am not gunning it every light either, so please don't insinuate otherwise. I firmly believe that these issues are a direct result of the underpowered nature of this vehicle. If it had another 30 horses or so, achieving decent city MPG would be well within the reach of the EPA numbers as you would not have to gently caress the throttle to get decent city MPG out of the car. Normal take take offs (We will say, for arguments sake, about half engaged versus the light touch I have to do if I'm fuel sipping) would not require as much oomph out of the little engine.
My 3.8 Genesis achieved 21 mpg on average in the city; my veloster sees around 24 / 25. Granted, highway is a night and day difference, but irrelevant for our purposes.
Otherwise, fantastic vehicle for the money.