If you query spritmonitor.de, you'll see
this, which for models made in 2005 and up, results in 45 samples averaging 5.72 l/100 km (41 MPG US-Gallon). Other stats-gathering sites may have other results.
There is a tendency on GH for some people to try to manipulate their results, either to make themselves feel better or to "race" the HCH-II against the Prius. 46 MPG isn't something you can count on unless you're a compulsive type.