Eco vs. Power Mode

Not really. The Owner's Manual sort of explains it on pg. 247. The Prius (including the Plug-in) is drive by wire, which means that the accelerator pedal does not mechanically control anything. Instead, a sensor measures the amount the pedal is depressed and software decides how to map the the accelerator pedal depression to how engine/motor speed. The modes simply change this mapping. ECO mode makes it the least sensitive (more pedal depression required for the same acceleration), normal (neither ECO nor Power mode) makes it moderatively sensitive, and Power mode makes it the most sensitive (less pedal depression for the same acceleration). In all the modes, if you put the pedal to the metal, the amount of acceleration is the same.

 

ECO mode also adjusts the HVAC system to be more efficient, thus using less power.

 

Not quite. Since the end points are the same, all that they do is MOVE the sensitive section of the pedal response. In ECO mode, the sensitivity is at the early portion, in Power mode, at the later portion. Normal is a more linear response curve.

With the exception of AC controls, a talented foot could have the car perform EXACTLY the same in any of the modes. If you don't have one of those talented feet, choose the mode the gets you the highest MPG (many find that the ECO mode does this, others find Power mode works better for them).

 

Good answers. The short version is that Eco and Power modes change the way the accelerator feels to the driver - they don't actually change the way the car works.

Also, as pointed out above, Eco goes cheap on air conditioning to save a bit of energy.

Tom

 

One note of concern: the PWR button is very close to the PARK button. I once was on an on-ramp, ready to go, so I pushed the PWR button to give me a boost. Only, it WASN"T the pwr button, it was the PARK button. I pressed on the accelerator and it went VOOOOM - but didn't move.
Do be careful with these buttons. It's better to set them before going into a busy situation requiring your full attention. Too bad they weren't located on the steering wheel instead.

 

How could they be further away from each other? I could see hitting the Hazard button maybe.



I leave mine in Eco to control the AC.. If I need to go fast, I floor it.

 

Hitting the Park button while moving won't damage anything. It just drops you into Neutral. I am surprised that pressing on the accelerator had any effect, given that it is just an input device to the control computer and not mechanically connected to anything.

 

With the Gen II it doesn't do anything. Perhaps another PiP owner will test this.

Tom

 

If you press the pedal far enough, won't it force charge by spinning up the ICE?

My Gen III does go vroom if pressed far enough. But in Park, the gas pedal dead band is large enough that an attentive driver should notice something wrong well before the ICE fires up.

 

I know it will do this in D, if you press both the brake and the gas. I'll have to try it again in P.

Tom

 

I by mistake hit the park button instead of the ev while on the freeway. Shifts into neutral and the warning lights come on. Scared the sh!t out of me. Luckily no damage.

 

There is absolutely no reason to press the power button when in need of a quick burst of energy. In fact, it takes longer for you to think about using Power Mode and press the button then wait for the car to change programming than it does to just floor the gas pedal.

 

LOL. I did this on the freeway. Pressing PARK just puts the car into neutral, but it's still unnerving the first time it happens. This is why pilots train and requalify every 3-6 months. Had it happened to me before, I would've known why the power suddenly dropped out (as well as the speed). But not knowing at the time that I'd hit the PARK button, I didn't know Wth had happened. Really poor human engineering on the location of all those buttons.

 

You actually need to let up on the the gas before the car will change programming. So you need to plan well ahead.

 

Like Bielinsk, I don't see what wrong with the relative placement of the Park and Power buttons. They are on opposite sides of the console, with the Park button all by itself. How could they have placed them more unambiguously?

Besides, as mentioned, using the Power button is not an emergency action; if you really need to move right now, just floor it.

 

I've done it without lifting off the throttle. It takes a few seconds to engage but if you hold your foot steady you can feel the surge when it engages. I agree that it takes too much forward planning to do anything effective.

 

You mean "Thanks to Toyota's thoughtful engineers, no damage", right?

 

I should have been more specific - it's not that the buttons are adjacent to each other, but when you simply reach over and hope to hit a button my "feel", then they all seem close together. Sorry for the confusion. Still, yes, it went "vrooom" because Park puts the transmission in neutral. I agree somewhat that by the time one thinks about pressing Pwr, then might as well just accelerate and this will have the same affect.
btw: Pwr mode really is powerful - I squealed my tires once on take-off.

 

Correct