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Discussion Starter · #1 ·
All of you veteran Prius drivers out there: I have had my '05 Prius for six weeks now and love it - but I have some questions about how my hybrid system acts and want to know if this is what is "normal":

1) After start-up, the car will not allow me to do any stealth driving until it is warm-up sufficiently now matter what the SOC is.

2) Driving down the highway at 55mph what I typically see is pink arrows from the ICE to the wheels and MG2 and green arrows from MG2 to the battery. This seems like a lot of energy from the ICE going to the battery when all I have on is the radio and the fan (and all the other electronics such as the MFD and the dash panel). Sometimes I can drive like this for more than 20 minutes and not even get any little regen leaves on the consumption screen. This is pretty much constant except for some pulses of yellow arrows from the battery to MG2 and from MG2 to the wheels. This will only occur when the SOC is 6 blue bars.

3) Sometimes even after the complete warm-up and SOC of 6 blue bars I find that I can not go into stealth mode (and I'm not going over 40 mph). For example, today I glided for about 1/2 mile into a small town and came to a stop sign. I turned left and accelerated to 25 mph and still had a SOC of 6 blue bars but I could not get into stealth mode - it was either green regen arrows or the ICE. Sometimes this happens, sometimes it does not. Any input on that???

Thanx
 

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Temperamental Prius

Temperamental Prius

My friend, you will receive a million reazons why that behavior from different Priusilians in this forum, and not of them will give a real vertical answer.
You are dealing with first temperamental automobile in history. A lot of variables are involved to get an stable behavior. If you take care of them you will be called for Rehabilitation from the Priusilytis.
I am not going to give you a response/explanation/answer, I am just going to give you an advice for free:

DRIVE YOUR PRIUS AND ENJOY THE RIDE...YOUR CAR WILL KNOW WHAT TO DO AT ALL TIMES....
 

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Wow, you get color coded arrows on your display? I'm jealous, my 2001 display only has one color no matter how big or small the current.

Your car's behaviour sounds reasonably normal.

Anyway, RMarchena's right, the computers are handling a lot of real-time information and adjusting things to the proper settings for you. Nobody but Toyota's engineers knows exactly what they do or why. As Bill Powell used to say: "Just drive it".
 

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It sounds normal to me. I don't get "stealth" mode above ~30 mph unless on a significant downhill, the ICE normally runs long enough to warm up at the start of a drive regardless of driving conditions (to reduce emissions they say) and whenever the ICE is running to move the car and the battery is not, some amount of regen is going on (per the green arrow) but the SOC does not change by enough to notice in a short period.
 

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Don't worry about it --- just drive it. Over time you will learn when you can act smarter than the computer and force the car to work slightly differently. Stealth is really not all that desireable as all energy comes from gasoline and there is an efficiency loss in going from rotational energy to stored energy and back to rotational. One of the few times it is worth trying to force EV mode is on a flat section just before you are going to power down the car. Since the car will insist on running the ICE after startup you don't really loose much in having a low SOC at this point. The only time you really want to regenerate hard is when you are going down a hill that has a red light or stop sign at the end. Here use the brakes to maximize regen is most efficient.
 

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As for some energy going to the battery on a high speed cruise, one thing to consider is that you are not able to see how MUCH energy is going in any direction. Consider the green flow to the battery as top-off energy.

I have often touted, even if only to myself, that not only should we be informed of direction of flow, but how much. As it is, the display is an oversimplification.

It was determined for the classic that in reality, the car does go into 'overdrive' by powering MG1 using MG2, thus allowing the ICE to run at a lower RPM. It hasn't been determined, to my knowlege if the 2G do that too.

Attilla, can you find out for us?
 

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eric29730 said:
1) After start-up, the car will not allow me to do any stealth driving until it is warm-up sufficiently now matter what the SOC is.
Yup, normal. You'll notice that your fuel economy is very low in that first 5 minutes or so as well. The A/F mixture is quite rich as more energy is being used to heat up the emissions control systems during that initial few minutes.

2) Driving down the highway at 55mph what I typically see is pink arrows from the ICE to the wheels and MG2 and green arrows from MG2 to the battery. This seems like a lot of energy from the ICE going to the battery when all I have on is the radio and the fan (and all the other electronics such as the MFD and the dash panel). Sometimes I can drive like this for more than 20 minutes and not even get any little regen leaves on the consumption screen. This is pretty much constant except for some pulses of yellow arrows from the battery to MG2 and from MG2 to the wheels. This will only occur when the SOC is 6 blue bars.
Here's the thing, energy will not go to the battery just to replace what you're using. The ECU tries to keep the ICE running within it's most fuel efficient rpm range. That may produce more power than is necessary to maintain your 55mph cruise speed. In that case it sends the excess energy to the battery for future use.

Also, if you are driving without slowing or stopping your should not see any regen leaves. Those only occur from coasting/braking. IMO, the fewer regen leaves the better. Think of it this way, if you never use the brakes and never coast (ie. just glide) you're taking maximal advantage of the kinetic energy produced by your ICE. The regen is only advantageous in that it's more efficient to recapture some of the kinetic energy than none of it when the reality is you must use your brakes to stop.

3) Sometimes even after the complete warm-up and SOC of 6 blue bars I find that I can not go into stealth mode (and I'm not going over 40 mph). For example, today I glided for about 1/2 mile into a small town and came to a stop sign. I turned left and accelerated to 25 mph and still had a SOC of 6 blue bars but I could not get into stealth mode - it was either green regen arrows or the ICE. Sometimes this happens, sometimes it does not. Any input on that???
Yea, me too. And I'm often hard pressed to explain why that happens. I will, if under 35mph, sometime use my EV button just to force the ICE off and that seems to keep the system happy.

A few folks have used the Idle Speed Recalibration and found some improved ICE performance and more rapid shut off of ICE when appropriate. I'll post those instructions below in case you're adventurous enough to try it. I haven't, but reports from the few folks who have have been positive.

"Idle Speed Calibration Learning Procedure"
Get the car good and warm (coolant
needs to be 83C, which I'm told takes a good long drive to hit). I
think it can also be reached by putting the car in Park and
stepping on the gas pedal to run the engine for a while.

Once the car is warm, put it in Drive, then with your left foot on the
brake, step the gas pedal down to about 75% power. Keep it
there for more than 30 but less than 40 seconds. The engine will
be force charging the battery during that time.

Then, power the car down, wait a little longer than 5 seconds, put
your foot on the brake and hit the Power switch again. Let the car
go through its normal startup routine in Park until the engine
stops.
 

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DanMan32 said:
Does that apply to the new Prius, or only the classic, or unknown?
AFAIK only for the 2G Prius and NOT the first gen ('01-'03). It also applies to the Lexus 400h and Highlander Hybrid.
 

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Re: Temperamental Prius

Rmarchena said:
You are dealing with first temperamental automobile in history.
Rmarchena never drove my super-temperamental '82 Nissan Stanza. Its most dangerous quirk, which occurred regularly but was never reproduceable by any mechanic, required me to let up on the gas pedal in order to accelerate. (This was not the usual lugging the engine scenario, but something much, much more dramatic.) This was the same car that mysteriously stalled on the highway on three occasions. It never occurred to me that it might have been national news. :wink:

As for Eric's questions: All are perfectly normal. For #s 1 and 2, Dr. Fusco is completly correct. As for #3, you were probably headed a teensy bit uphill, which makes the car want to use the ICE. See if you can go into stealth on the same stretch of road going the other direction. The Prius is remarkably sensitive to changes in gradient - there are roads here that I used to think were flat, but on which I get 40 mpg one way and 60 mpg the other.
 

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Mark,
I've actually experienced the situation in #3 (ice won't shut off to allow glide) many times while going downhill...I was trying to 'get my glide on' and it just wouldn't quite giving me arrows from the ICE.
 

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Discussion Starter · #13 ·
Wonderful feedback

I really appreciate everyone's feedback to my concerns. Kinda reminds me of the type of feedback you get from watching the MFD in the Prius!

Evan, thanks for posting the "Idle Speed Calibration Learning Procedure". I doubt I will try doing anything like that, having had the car for only 6 weeks, but at least I know where to find it and that it actually exists! But may I ask why you have not tried it? Also - do you like the EV switch? How often and under what conditions do you use it? Don't you have to pay Paul after robbing Peter???

Thanx again :)
 

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I told ya...eric29730

I told ya...eric29730

My predictions were right Dear eric29730. You heard a lot of things and you end up as you started, Knowing Nothing. At least you know something that you did not know how no to know your Prius. Something is better than nothing.

One day Toyota Motor Co. will release a book with one of the following names:

"PRIUS SECRET CODES"
"CODIGO DA'PRIUS"
"PRIUS FOR DUMMIES"
"PRIUS UNDERGROUND"

I will prefer "CODIGO DA'PRIUS"
 

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"My predictions were right Dear eric29730. You heard a lot of things and you end up as you started, Knowing Nothing."

Well, rmarchena, speak for yourself. YOUR posts contained no useful information, just insults to the car and those who contribute constructively here. The other posts explained that it is normal and cited why. Did you not read them, or not understand them?
 

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Re: Wonderful feedback

eric29730 said:
Evan, thanks for posting the "Idle Speed Calibration Learning Procedure". I doubt I will try doing anything like that, having had the car for only 6 weeks, but at least I know where to find it and that it actually exists! But may I ask why you have not tried it?
I dunno, not sure I need it, a tad worried I'll do it a little wrong and trigger a DTC or something. I think my car behaves appropriately so I'm more or less in the "If it ain't broke don't fix it" mode. Maybe I'll give it a try next week and report back just to say I did it.

Also - do you like the EV switch? How often and under what conditions do you use it? Don't you have to pay Paul after robbing Peter???
My thoughts on the EV button are long, complex and convoluted. I use my EV button a lot, but probably not in ways that many people would expect. I think there are times where you can 'out think' the ECU and improve the efficiency minutely by judicious use of the EV button.

For example....I can turn onto the ~1/4 mile long street that goes to my driveway and ultimately my house and glide/coast the entire way to my garage. Except there's a very small rise half-way down my ~150 ft. drive. When I turn onto my driveway I'm usually going about 12mph...if I try to glide over that sometimes I make it, but sometimes I lose so much speed that I end up needing a little boost to get over the hump. If I didn't have the EV button some of the time the ICE kicks in...I take an electrical hit from the battery to start the ICE then I take a gas hit for that brief ICE burn. With the EV button I just take the tiny electrical hit from the battery to get me over the hump and completely avoid the ICE/gas burn.

I have a number of situations in my routine commutes (dropping off kids, work, etc) where I've learned these spots where ICE is really not necessary and is clearly more inefficient if it does come on than just using the electric motor alone.

I also use it when I'm approaching stops where I know I'll be waiting a while for a light to change or whatever. The computer isn't programmed to anticipate stops and thus the ICE would run until the car had been at a stand-still for several moments. I, OTOH, can force the ICE off 100 yards before the stop while I glide/coast/brake to the stop...thus eliminating several seconds of ICE burn. Not a lot of gas once, but over time I believe it adds up to a minor amount.

Finally, I tend to use it in parking lots. I grab my kids and pull out of my parking place and move 50 feet to the road where I wait to merge into traffic. Normally the ICE would be in forced run mode for the emissions warm-up and such....burning gas but going nowhere. Instead I sit using electric only, as soon as my opening in traffic comes I punch the button or just hit the accelerator a little firmly and the ICE immediately comes on and goes through the warm-up while I'm moving. I believe that more efficiently warms the emissions control stuff and shortens the time the ICE is forced on. Another tiny gain.
 

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efusco said:
Mark,
I've actually experienced the situation in #3 (ice won't shut off to allow glide) many times while going downhill...I was trying to 'get my glide on' and it just wouldn't quite giving me arrows from the ICE.
You're right, which is why my reply included the weasel term "probably." But as a rule the Prius is more difficult to get into stealth going uphill than going downhill.
 

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What I want...

What I want...

I would like to have control over the Prius I purchased.

Of course and reading your posts and everybodyelse's, otherwise I would not respond them. But, there is a different in my readings. I can see between lines what members ask and what kind of responses they use to get. They get resignation and conformism answers about controlling Prius's behavior. It looks like some irritation shows up as soon I read and say what I see between lines.
Everybody wants to have some portion of control over what it is been purchased. In Prius's case looks that is very misteriously limited due to "DA'PRIUS CODE" which a few people knows about (I do not know if I include Prius's Godfhaters, Gurus and Soldiers).
Normaly, when a response is about Prius's intrinsics, it contains five or more variables that is easier to forget about than follow up.
If anybody denied the purchaser's right to control, at decent level, what He/She obtained with a shape of a Prius is totaly mitical, misterious and insane.
I and many owners want more control on Prius's behavior...!!!
Is it something wrong with that?

I think we are entitled to have that control, and in another way,to post in the "General Chapter" of this forum not only Prius's technical aspects. I am not obligated to follow up in questions which answers are in the owner's manual or in the less common of all the senses, The Common Sense.
The reazon why We have different ID's is because we have different perception of reality including our beloved Prius.
 

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Discussion Starter · #19 ·
Situation #3

As for situation #3 in my original post - today it happened when I even had a SOC of 7 green bars.

Today I took my first extended trip in my Prius - to see how it reacts in a different environment. I filled at a different gas station this time at 1 pip (not blinking), 62.0 mpg (MFD), and 620.0 miles. I put in 9.302 gallons - that would be 66.7 mpg. But that would be too good to be true since the previous fill was at 1 blinking pip, 62.0 mpg (MFD), and 626.1 miles - but where I usually fill up, I put 10.597 gallons or 59.1 mpg. There's a testimonial to different pump cut-off pressures!

Back to my trip, 2 pips left, 59.7 mpg (MFD), and 466 miles. Drove 55 mph with CC with sporadic periods of rain and temps in the 60's. Started at sea level and ended up somewhere here in West Virginia - whatever the elevation is here. I started at sea level and when I got to the top of Mount Something-or-other (elevation 2780 ft) about 200 miles into the trip, I was at 60 mpg. I'm pleased. Tomorrow comes the return trip - different route tho. I'm gonna try some winding mountain roads instead of interstates.
 
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