My Civic is doing 0.0 L/100km. That means the car can run only on electricity. Engine is idling.
The trick is to keep speed constantly on 43-44 km/h (about 28 miles per hour). Then "assist" wakws up and 4-5 bars are on. fuel economy meter drops to zero and computer shows 0,0 L/100km.
Battery drains quickly, you can drive this way only about 5 miles (have not had a chance to test this on longer street.
You must be werry gentle with throttle or you must turn on cruise control.

check out my video. I made this today. quality is poor, but it still shows everything
http://www.youtube.com/watch?v=X8lGjfJCwP4


PS fuel economy "gauge" is working opposite way in Europe. If all the lights are on, it means high L/100km(poor mpg) and vice versa