Over a 11 month period: 11,9 kilometer per liter (don't know the conversion to miles per gallon)
Includes: 30, 50, 60, 70, 80, 90, 100, 120 and 130 km/h zones, flat outs, warm ups, 6 km distance and further and nice behavior driving.
Best ever on a tank was 15,0 kilometer per liter, worst was...