Local drive for me in Western Massachusetts is 6 miles each way so I am not even able to warm her up. I am getting 46 MPG at speeds of 35-45 mph. Non-city, non-highway. I just drove into NYC a 3 ehour drive and got 62 MPG with 4 passengers at 57 MPH into the city and 62 MPH home.
You did better than me. Last summer, I drove to Boston from NY and got 60 MPG. All highway around 60 MPH.