Meh, I guess EV is only useful depending on where you are driving. Like I said, I have a 5-6 block stretch on my daily commute that I can go completely on EV without depleting the battery. What's nice about this is that if I wasn't in EV, I would definitely be firing up the ICE since the battery acceleration is just not good enough in any other mode to keep up with traffic. I'll try to see what my realtime MPG gain is from using EV in this area. I'd imagine it has to add about ~.5 to a tank if it's a good mile every single day that would otherwise be more in the 55mpg range at best.
I use EV mode to move the car in the company's car lot when going to the company's gym - it's about 1km or so. When I take the car after the gym, the ICE needs to warm up in any case so it will charge the battery as well and I save the fuel and the engine when moving the car from one spot to the other. On another normal car I would have to turn it on in any case, let the engine run while I move the car and then turn it off again after probably less than 2 mins. Not very fuel and environmentally friendly. I need to move the car in any case as it is on the way home. In this case EV mode is helpful to avoid the ICE coming up at all. Other cases where it is useful, when you need to move the car to do something. Otherwise no much more need of the EV button. But, since we can do it, compared to normal cars, I like it this way. I also know that the battery will not deteriorate, because in normal driving the battery goes into the same charge/re-charge several times and when the level is low the engine will start in any case. With the difference that there is no notification that "EV mode not available at this time, battery low".
The electric travel in ECO mode is obviously superior, allows higher speed and longer range before ICE. I think the EV mode is preparation for electric only, perhaps plug in operation. However, the Prius has full safety considerations including crash tests; and there is no need for NEV restrictions. :rockon: I think the EV mode should operate without shut down conditions. Perhaps there is some battery and motor specs which must be handled, but the software should address that and allow full startup throttle and high speed otherwise. There is no need for the wimpy EV mode, Toyota. Get over it.