[MetroMPG]

Of course you're right: the final word goes to miles divided by gallons at fill-up time.

But if you want the most useful feedback between fill-ups, use a resettable, properly calibrated digital fuel economy gauge. The overwhelming majority of "high MPG" drivers here use them for that reason.

Saying "I'm not getting but more then 30-35 mpg" by the position of the needle on the fuel gauge just isn't accurate or timely enough to use as feedback.