I might be wrong, but from what I have read about the Honda Hybrid system, it is on all the time. The electric part and the engine are on the same drive shaft (the electric part is helping the engine all the time - however the amount of help varies based on conditions) unlike the Toyota system where either one or the other is providing power to the wheels. In the Toyota system there is a switch over form electric to engine depending on the conditions (usually around 60km/h or so). Please note, I don't have any first hand experience, just what I have read in the net.