Toyota Prius3 fuel consumption in mixed mode

The New Car Features manual.

Toyota Service Information and Where To Find It | PriusChat

 

Maybe its different for other Prius's, but ECO mode on my 2011 is very telling from normal mode. On normal just barely hitting the gas starts up the gas engine. On ECO takes much more foot pressure. Could be the state of my hybrid battery as well, its been weak for a couple years now - just waiting to replace it.

 

That's the difference between the linear 'normal' and the concave-up ECO calibration seen in the graph below. You can see the initial pedal movement in ECO must be much further to reach the same motive force request where the engine will start.

 

In summary: Your right foot controls the car. Not some silly buttons.