Its maybe just me missing something completely obvious but the mpg read out on the dash display on my D2 never goes above showing 50mpg - yet if I select the drive stats on the MY CAR option on the main screen it will be reading a different MPG - I've tried resetting both but doesnt seem to make any difference - today on the way back from work - dash display sat at 50mpg and on the main screen I was getting 63mpg (as an average). Any suggestions? Thanks