With about nine months of data my 2.3L Mazda 3 Is averaging 21.10 MPG compared to the last 6 years of data i have for my 3.1L Beretta (1990) that averaged 15.63 MPG. The Best MPG’s on a Tank for the Beretta was 23.64 compared to the Mazda 3’s 34.35 MPG.

See this Chart for my Mazda 3 Fuel Economy.