I can't figure out what that little button does that is so special? It kicks me out of ev mode for "excessive speed" or "excessive acceleration" or just because (which can range from engine temp to battery charge level, etc.) so often that there seems to be no difference between using it and just keeping the little bar thingy on the display left of center when driving at low speed. Am I wrong or does this thing do nothing I can't do with my foot?
The main purpose of this button -- at least for me -- is to prevent the engine from kicking on when I am moving the car in and out of the garage to wash it ... or, if I am moving the car only a very short distance (like from my parking lot at work to the loading dock).
EV mode allows you to go up to 25 mph on only battery. It won't work right when you turn on the car and it won't work if accelerate too much. It's good for driving in a parking lot or somewhere where you need to go slow for a short period of time.
For scaring teens crosswalking the parking lot at Tim Horton's. Less efficient at night in Canada though, we can't kill the DRL's...
I use EV mode on the scenic routes at National Parks to enjoy the wildlife. One time a grey wolf stood by the brush while we drove around a blind corner and never got up to leave. I took a picture, drove away & the wolf was still sitting patiently in the bushes.