What Is "Normal?"

If you drive based on how pedal feel (i.e., you tend to determine how much you're going to accelerate based on how far you feel is appropriate to press the pedal in any particular circumstance), then you might save some in ECO mode versus normal, as long as ECO doesn't cause you to become too conservative with your acceleration. (Yes, being too conservative with your acceleration can reduce efficiency. In particular, always attempting to avoid causing the engine to turn on is actually not a good idea, except perhaps in a few very specific cases.)

If you're like me however, and judge acceleration by the feel and sight of the accelerating motion itself (along with watching the HSI), then your choice of mode doesn't matter (much). In ECO mode, to accelerate at a certain rate, you simply need to press the pedal a little bit farther than you would need to in Normal mode. But nothing changes as far as engine operation is concerned. It's all a matter of what pedal position is mapped to what level of power request to the engine. Once the car figures out how much power you're asking for based on your mode and pedal position, the engine does the exact same thing no matter what. Additional power in PWR mode is an illusion, technically, since nothing prevents you from getting the same amount of power when in ECO mode; just press harder on the pedal. (If you floor the pedal, it doesn't matter what mode you're it; they all produce equal power at that point.)

There are a few real benefits to ECO mode, such as altering how the AC runs, when the engine shuts off at a stop, et cetera, so there is a true but small difference between the efficiency of ECO and the other two modes. But in terms of basic engine performance/efficiency, there is really no fundamental difference.

 

Did I miss something. I don't think I've seen a reply with a good explanation of "normal mode" (absence of dash light selection EV,EC, or PWR). This is going out on a limb, if I select ECO and it lights up on the dash fine. Now if I press ECO again the dash light goes out for ECO. Is it possible I'm still in ECO just driving without the annoying ECO light lit up?? I wonder if my theory will prove true in PWR mode, if PWR on dash is lit then I press PWR again light goes out will I still feel that available power ? Forgive me if I sound foolish, just a newbie learning.
Thanks Joe

 

If the mode lights are out you are in normal mode.

Tom

 

Are you certain that the maximium "floor" power is the same in all modes? I ask because it seems like I read somewhere that the maximum power was limited in the ECO mode.

 

:welcome:

 

I don't think so. I'm pretty sure that when the car is at WOT (Wide Open Throttle) you're going to get the same output regardless of operating mode.

 

Yes, it is the same. I was personally told this by the Prius Chief Engineer when we were talking in Detroit.

The reason is obvious. Regardless of mode, if you need to move in an emergency, you need full power. Taking time to hit a button is not a good option.

Tom