Mine seems to keep getting more fuel efficient with every additional km. I'm close to 30000km now and this week recorded my highest mileage on a tank thus far. I was 2km shy of hitting the 400 mark when she hit reserve.
She's now at 35km of reserve, but I don' t think I'll be letting her run dry to see how far she will go on the full tank.

Assuming that reserve is the advertised 6l and the tank is indeed 23l that brings the economy to about 4.25l/100km.