both cars have different technologies....honda has IMA while prius uses a HSD or hybrid synergy drive. now here is the main difference;
in IMA, the electric motor is there to "assist" the engine maintain speed which is under 40kmph, anything over that the gasoline engine will come to life. Also starting from a 0, the car will always use the gasoline engine since the electric motor is not powerful enough to pull the car on its own..
on the contrary, the HSD has the electric motor which can push the car from zero to a reasonable speed and can maintain it there until either the car runs out of juice or the speed crosses limits of the electric motor.
this way, prius can be more fuel economical.
