You are doing great so far. More than 80 mpg and under the 3L to 100 km mark on the last tank.
Slowing down to 100 km/t / 85 km/t would yield even better milage.
Maybee its time to start to do some work on the rear end of the car. With the boxy shape it has, the rear is where you can find real good gain, as seen here where the difference between the 3L hatch and the standard are shown: