Different routes, different mileage

Sometimes I read posts of people disappointed by the mileage results of their Yaris Hybrid.
Results are heavily influenced by the kind of your average trip.
By comparison, in this season, my daily commute home-work-home, a 9+9km trip on urban and plain suburban roads, scores 4.2 l/100km.
A different trip, home-countryside-home, a slightly longer 12+12km trip on urban and hill roads, scores 3.8 l/100km (with A/C on).