All the Vancouver winter I idle it for 5 min, at 1000-1100 rpm. (don't idle it at low rpm - it won't be enougf oil pressure) Another 5 min - slow, moderate driving.
In the winter my truck makes 8km/l, driving mostly short drives 7km to job and back. In Summer it makes 11 km/l.
Pajero1, 1990, SWB, Auto, 265*70*R15