@Rajan, It was not network assisted GPS. So I guess the speedo calibration is incorrect in my set up. @anoop, in fact I have another interesting observation. Always when I re-filled from bangalore pumps, the actual FE calculated has been lower than the MID value. However, when I re-filled from the Kerala, it has shown above MID value (3-4 re-fills in last trip). Does it by any means show that we are getting more accurate quantity from Kerala pumps and not so in Bangalore? Another possibility could be that for long drives the MID calculation formula is towards lesser optimistic side and for city driving, it shows much more optimistic values. Or there isn't much to any of it and its just happened so in some of those runs/refills.