Check the O2s, the Air filter, the fuel filter, and the weight on the accelerator.
Around town & similar short distance driving, this is about normal. If you get around 30 on the highway, then you know its ok. These cars have significantly better highway mileage. I drove 130 miles the other day on a quarter tank, with 2 gallons to spare! But in town, I'm betting on 14 mpgs..