Our 2011 Sonata GLS gets an average of 13.5 mpg. Just to be thorough, we drive 60 mph on the highway, in the "city" there is no hard acceleration or braking. There's nothing in the trunk, no towing, not more than two passengers, no a/c on, and no windows rolled down. The tires are inflated to 32 psi as per the manual's recommendation and the fuel is brand name of the octane rating recommended in the manual. We have garnered these results over the 900 or so miles the car has on it. I have both used the Sonata's average mpg display and via meticulous record keeping of gallons filled into the tank over the course of the car's life. All other things being even, we bought the car because of the mileage. If we wanted this kind of mileage we could have bought a big truck with a massive V-8. Shame on you Hyundai.