At startup, my 2016 S e-hybrid will drive in e-power mode and go that way for the duration of its charge, perfect for 12 mile commute. If I manually downshift to more rapidly accelerate up the hill outside my street, the car shifts to hybrid combustion mode and then returns to e-power electric mode a minute or two later as expected since e-power was not deselected. If, however, I floor the gas pedal beyond the detente while in e-power mode to recruit the combustion engine in accelerating up that hill, the car will not return to all electric driving for 5-7 minutes and a good 5 miles. It defeats the purpose of being able to recruit the combustion engine on an as-needed basis while maintaining efficient electric use during my commute. Anyone else experiencing this? Is this a problem or is this the way it is designed? It certainly suggests that I should never floor the accelerator past the detente if I want to drive thereafter in electric mode at all.

 

ICE should work during that time in idle rev mode and it is not engaged in running the vehicle. During that time engine is preheated so oil and other fluids are warm. That protects engine to be turned on and off while cold.