 I bought my 2011 Elantra in January. My mpg averages 27 in the city and as high as 37 on a 600 mile trip. I'm not getting the advertised mpg.My major compliant is that the car's engine vibrates at idle with the air conditioner on and the engine is hot. Very annoying. The steering wheel vibrates and the driver's side seat vibrates.I took it to dealer service dept to have this checked out and was informed that there was no fix. The car has no idle adjustment. I've owned cars this size all my life and it's been since the 70s that I've owned a car that vibrated. Obviously the engine is not powerful enough to carry the load of the air conditioner. Cute car, but don't let looks fool you. 