Introduction
The Prius is well known for being the champion of all hybrids in terms of fuel economy (FE). It is equiped with nice, real-time gauges that inform the driver about the way he drives. The system is aimed at providing instantaneous feedback to help him achieve even better fuel economy. But the Prius is also equipped with a more conventional trip computer, that displays the average fuel economy since the last gauge reset. That tool is useful for those (like me) who like to monitor the amout of fuel they use on a daily basis.
When the Prius 2010 was introduced, some owners noticed there was a difference between the value displayed by the fuel economy gauge and the actual amount of fuel one could put in the tank [1]. One could expect such a difference, as the amount of fuel measured by the pump at the station may be erroneous. However, several chatters said that the fuel economy gauge display was consistently more optimistic than in reality.
To better understand the problem and perhaps identify potential causes, I have started a little experiment.
