EV Switch ?

I believe the EV function works the same on all Prius, whether you install it yourself (US) or the factory does it (Japan, Europe).

When I engage mine (flash the headlite lever), it beeps once and MFD switches to the Energy screen (where the battery level is shown). It then will stay in EV mode up to 34 MPH OR until you're down to 3 bars on the hybrid battery, at which point the gas engine kicks on automatically. Also, if I am accelerating too fast or trying to pull a pretty good hill, the gas engine automatically kicks on.

I can also turn off the EV mode manually by flashing the headlite switch again. The engine then fires up.

The whole system of protecting the battery pack and ensuring the engine is warmed (for emissions) is cool! If I try to engage EV mode with lower than 3 bars or with a cool engine or for other reasons that I'm not privy to, then it beeps 3 times at me and will not engage EV.

Love the extra geek feature of EV mode! I mainly use it in the morning to delay the engine start until I'm on a 35 MPH roadway. Then I use it at the end of my commute in my work parking lot. Plus at the grocery store it's awesome to cruise in EV mode and watch the heads turn to see how that car is moving with no sound.

 

I think the original question is still unanswered:
You are humming along at 30 in EV button mode. The ICE kicks in when you go 40 MPH for a while then you go back on a 30 MPH street.

Would you have to reengage EV mode, or has it remembered that you started out in EV and will ALWAYS use EV when possible?

 

When the EV mode has been automatically canceled with three beeps, it won't go back to the EV mode again if the condition (speed, batt level, heat etc.) is cleared.

Tosh
04 Salsa BC
San Diego, CA

 

As commented earlier, the EV button (or any other form of EV switch) toggles in and out of EV mode, but the computer may refuse to go into EV mode, depending on conditions, and also may take you out of EV mode depending on conditions.

Your wish for the car to always go back into EV mode, once selected, flies against the characteristics of the car and the reasonable use of EV mode:

You will only have a mile or so of range in EV mode, under the best of conditions, and MG2 by itself does not have much power. It is a very bad idea to try to maximize the time spent in EV mode. Under normal conditions the car functions best in hybrid mode, with the ICE running as the computer decides, and the electrical system charging and discharging according to conditions.

EV mode is desirable only under very limited circumstances, and only for relatively brief times. It is therefore really much more convenient to have it remain out of EV mode once it leaves that mode, until the next time you choose to engage it.

 

Daniel nailed it. The battery capacity is equivalent to a few (2 I think) ounces of gasoline. EV is a novelty and useful in only a few instances. For example:
I live and work only 1.3 miles apart, but every workday I drive to one meeting or another, and most evenings we go somewhere. So, in the morning I ghost out of the garage in EV mode and drive to work. The ICE never comes on. During the day my drive charges the car. That afternoon I ghost home, backing into the garage in EV. Neat-o.

 

<div class='quotetop'>QUOTE(tntna\";p=\"54090)</div>

You'll change that comment once your 2005 is broken-in.

My 2004 clearly out-stealths my 2001.

After 85,000 miles of Prius driving, I've found there are only a handful of circumstances where you'd benefit from EV and a whole bunch of them where EV could actually cause MPG to be lower. So I don't recommend the EV button.

 

To be "broken-in", you really need at least 10,000 miles.

Lack of education is the detriment of EV. That will be overcome, later. Right now, we still have a bunch of owners that still don't understand "brisk" acceleration. So eliminating that misconception is clearly a higher priority. Skipping steps is rarely helpful.

And no Evan, I haven't decided against. I simply don't recommend it. My confidential sources have educated me about the current market. And that is what I wish to help. Later, I still could add it. But right now, that would taint my real-world data. That is an obvious negative. So I have refrained.

 

To digress a bit, wouldn't it be safe to say that there is still considerable controversy over the notion that brisk acceleration will increase gas mileage? For starters, Toyota recommends moderate acceleration for the Prius as a fuel conservation measure.

<div class='quotetop'>QUOTE(john1701a\";p=\"54319)</div>

 

What does "moderate" mean?

We have identified "brisk" as roughly 70% of engine potential, which is about the optimal speed it can run at under an acceleration load.

Is that the same?

 

I guess I am going to have to be more precise in my language! On page 235 of the owner's manual, Toyota advises to "Accelerate slowly and smoothly. Avoid jackrabbit starts" to improve fuel economy.

My only point is that I've followed the "accelerate briskly" debate for a few years now, and I still have yet to see anything that really convinces me one way or another (though I do concede your mileage is a couple of mpg better than mine...). For me, the jury is still out.

This, of course, has absolutely nothing to do with EV switches!

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