Why is the Ford Fiesta's fuel economy not as good as advertised?

I recently purchased a Ford Fiesta and noticed that the fuel economy is not as good as I expected. It is advertised to get 37 MPG, but I am only getting around 30 MPG. Is there something wrong with my car or is this a common issue with the Fiesta?

It is possible that there is something wrong with your car, such as a faulty oxygen sensor, which can affect fuel economy. I suggest getting it checked out by a mechanic.

I have found that the Fiesta's fuel economy can vary depending on driving habits and conditions. Make sure you are properly inflating your tires and avoid excessive idling for better MPG.