^^ that, and your driving habits.
Also depends on model years. My Mazda3 (2010) gets ~7-8L/100km combined. If I hypermill, I can get into the low 7s, if I drive like I don't care, it's in the high 8s. Pure city will be in the 9s. The "skyactiv" (2012 and later) models will do better.
There are too many variables to answer your question specifically.