In my experience it can go upto 16km/l on highways at speed 100-120km/h (approx). Ref: CULTUS 2009 VXL, michelin energy XM2 tyres (175/70/R13), with two adults and three kids, 2-3 bags in diggy. Route: Khushab to Sargodha, Sargodha to Makhdoom interchange, Makhdoom to Lahore