With regards to the discrepancy between claimed and real consumption, this is common to all manufacturers and will documented. With regards to your satnav, it sounds like you may have an uncompleted route that needs cancelling. From the satnav screen, select menu, route, then delete, and finally yes. The system is not that intuitive but it's reliable enough once you get used to it. Sent from my LG-H930 using Tapatalk