Depending on the speed you drive on the interstate and how aggressive you are in the city, your MPG should be between 19-21 combined.I have 419 miles now on my Limited Powerboost and driving mostly in Eco mode and attempting to drive with fuel efficiency in mind, I have only averaged 19 mpg. I hope that improves as it breaks in or maybe I need to lear how to drive a hybrid. If any one has pointers they would be appreciated.
Also, you said that you’re driving “mostly“ in Eco mode so that will also make a difference.
Remember, the sweet spot for EB engines on the interstate is between 50-60 MPH.