Why does my 2013 Kia Rio lx hatchback get such terrible fuel mileage?

What is your question?

My 2013 Kia Rio lx hatchback averages roughly 12 mpg combined. I purchased this vehicle 2 months ago and cannot seam to find any answers as to why the fuel consumption is so terrible. A/c switch and light are always on every time car is started and i have to manually turn it off. Inside dome light works very intermittantly. Slight ping heard in engine durring acceleration.

What makes this problem better or worse?

It feels as if something is dragging this vehicle down, like THE brakes partialy engaged. Automatic transmission and when i'm driving on the freeway and going down hill car will begin to slow down very noticeably when i take my foot off the fuel pedal.

How long has your 2013 Kia Rio had this problem?

Since purchase 1000miles ago