Topped up the Prius V in Douglassville, PA on Friday 9 June. Contrary to an earlier post, there is a substantial increase in MPG when using E0 with the Prius V. Other Prius owners clued me in to this years ago. My son's Honda Accord also shows improved MPG on E0 fuel, albeit not as much. I think it has a lot to do with the engine design and the electronic controls.
My Ford CMax Energi sees only E0 becuase it goes so long between fills. The last fill was on 27 March and it is down half a tank after 1650 miles of driving. This tank is likely to go 5 months unless the car is taken on a long road trip. Just imagine how much water vapor could be absorbed by the Ethanol laced E10 fuel over those five months.