I've posted about this before... and it happened again today. This occurs at low speed, descending a hill with the engine cool. Someone suggested that I shift the transmission into "S". This DOES work. The gauge immediately goes back to full mpg (all bars).

Some have said this is a calibration mode. I'm wondering if it's just a flaw. It might also be contributing to the fact that all HCHII's report 1 - 2 mpg lower than calculated MPG. Perhaps these periodic "space out's" of the meter are more common than we realize (not looking at the gauge every second!) and cumulatively, they add up to the 1 - 2 mpg deficit per tank???

If someone here with an HCHII uses "S" mode regularly, can you comment on how far off your MPG readings are (meter vs. calculated)? If you're closer than the typical 1 - 2 MPG, then I might be on to something!