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Newbie Qs for Smacking New 05 Prius

Discussion in 'Gen 2 Prius Fuel Economy' started by Uncle GroOve, Dec 5, 2005.

  1. Uncle GroOve

    Uncle GroOve New Member

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    Hello folks.
    Swiss newbie here, freshly engaged to his silver '05 Prius since saturday :D

    Fine group you are, really. I have enjoyed reading through many informative posts over here.

    My main Q concerns the way in which the HVD switches in ("flickers"?) every now and then.
    From what I've gleamed, it is not advisable to discharge the battery (unless where really needed) so it does not make any sense to see it "flicker" in action every now and then.
    1) Why does this happen?
    2) Is there any way to "tune" the programming so the overall system performance is more in sync with my main driving conditions (some highway, local roads, congested traffic, appx. 56 km / day)? My aim is to have more main battery available when I'm driving in congested traffic

    Just another Q re. best strategy to optimize EV usage when driving in slow traffic:
    Is it better to inch along (in EV mode) or to wait for a gap to form in front and then engage in a "kick-and-glide" thing?
    I've realized that the main battery is drained pretty quickly - especially when approaching the threshold speed of 45 kph / 28mph.

    TIA

    Uncle GroOve
     
    #1 Uncle GroOve, Dec 5, 2005
  2. efusco

    efusco Moderator Emeritus
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    Uncle Groove,
    As to the second part of your question I think it all depends upon how slow the traffic is and the likelyhood that it will pick up soon. Frankly, I usually go ahead and hit my EV button and see how far I can go on that. Once it's drained then the car will do it's own thing anyway. If traffic where you live is patient enough to allow you to open a km or so gap then 'kick-and-glide' probably is pretty efficient. 'Round these parts that'll get your butt kicked!

    As to the first part...I'm confused by the question and I don't really know what you're asking. "HVD" is an acronym I'm not familiar with. And I don't know what you're trying to say is 'flickering'. Do you mean that the display itself flickers? If so then that is definately not normal.
    Do you mean that the State of Charge (SOC) of the HV battery moves up and down a bit--then that's totally normal and not really something you should worry about.

    The second part of the main question involved moderating your HV battery discharge and charging. When conditions allow (ie slow speed) you can always use the EV button to anticipate hills and such. But otherwise there isn't much you can do. Just let the car do it's own thing--it does a pretty good job. As you gain experience driving you may find that you can control the SOC a little by varying your driving technique...but that's a year or more down the road in all likelyhood.
     
    #2 efusco, Dec 5, 2005
  3. Uncle GroOve

    Uncle GroOve New Member

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    I'm sorry.. I just reread my post and I realize it is indeed a bit confusing.
    What I meant with my first part of the question is that I see the arrows indicating power being contributed to the ICE switching on very briefly (1-2 seconds at a time) in conditions where this contribution makes no sense whatsoever.
    I appreciate the fact that Toyota's engineers really worked things out to a great extent (reason I chose to purchase my Prius in first place!) - I still believe that such a feat of technology should be tweakable to local / specific conditions.
    My daily commute's conditions for example are radically different from someone driving 120 miles a day, mostly on rural, flat, medium trafficked roads...

    Thank you again!
     
    #3 Uncle GroOve, Dec 5, 2005
  4. efusco

    efusco Moderator Emeritus
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    Ok, that helps some, but you shouldn't ever see arrows going to the ICE...too the wheels from the ICE or too the wheels from the battery or both. Or from the wheels to the battery, but never to the ICE (although power does, indeed go to the ICE from MG1 that is not reflected at any time on the display).

    Still, although it may not 'make sense' to you it is probably occuring for a good reason. The ICE may not be warmed up or the Catalytic converter, or you may be traveling over 41mph such that the ICE must spin to prevent MG1 from over reving. You just aren't telling me enough about the specifics of the situations that you're seeing this 'anomaly' occur to say exactly what's going on.

    And yes, for many of us it would be nice to be able to 'fine tune' the system based upon the conditions. But honestly most people would either be confused by it, do it wrong based upon their conditions resulting in worse gas mileage, or both. You're lucky that the EV button is standard in the Europe...we don't even have that in USA to help control our car unless we add it ourselves.
     
    #4 efusco, Dec 5, 2005
  5. Oxo

    Oxo New Member

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    After a couple of months with my new Prius I've come to the conclusion that using the EV switch is usually a waste of effort when you're in very slow traffic. The car will go over to EV anyway when it can so it's best to leave the decision to the car. I now use my EV only to impress someone who gets in for the first time (I switch on EV so that we move out of my drive in complete silence). I also use it on occasions when I'm just moving the car a few metres for any reason.
    The other conclusion I've come to now that colder weather is with us, is to leave a/c switched on all the time. When I first had the car I was frequently calling up the climate screen and changing the fan speed, etc., but now I realise I can just let the car make its own decision about the right thing to do. The default temperature is set at 19C (66F) which I find just right.

    In short I've decided: "The car knows best". Like Mother.
     
    #5 Oxo, Dec 5, 2005
  6. Jack 06

    Jack 06 New Member

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    Ooooohhh: "The Mother of All Cars"

    ::frantically looks for Toyota Marketing phone #::
     
    #6 Jack 06, Dec 5, 2005
  7. Uncle GroOve

    Uncle GroOve New Member

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    I did see it happen very often this evening on my way home. It's almost annoying. Downhill, uphill, straight along.
    The "yellow flow" switches on at irregular intervals which to me look totally random and illogical. And this even though the main battery isn't fully loaded (I could easily understand the logic of this specific case) - and of course, the more this happens, the less chances there are that I manage to get the battery fully loaded.
    To this effect I was only able to attain a Full Green SOC after a little hill, which was steep enough to briefly engage the B-switch.

    After the highway stretch I was only 2 notches above "50%" so when I exited onto the regular road and the traffic stalled and I engaged EV, I immediately used 2 notches for half a mile. Not a record I feel particularly proud of - especially since the logic behind my purchase is to manage to use the EV for the last 3 miles home, for example :huh:

    I do not wish to convey the image of a whining brat - I do love the technology for what it can do to help the environment and keep my fuel costs down (over here= $1.25 / liter).
    I just want to be able to use it effectively AND to know if it is (who knows?) not functioning properly.

    On a positive note: I am enjoying a more relaxed driving style and concentrating more (in a positive way) in improving my mileage score...
     
    #7 Uncle GroOve, Dec 5, 2005
  8. aaf709

    aaf709 Ravenpaw of ThunderClan

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    Wasn't that a 1928 Porter? Oh, wait, that was My Mother The Car. Sorry, about that, carry on. :)
     
    #8 aaf709, Dec 5, 2005
  9. windstrings

    windstrings Certified Prius Breeder

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    Hi Efusco.. I have a question about your statement I've been wondering about.

    When the EV is engaged and the batt drains and the car takes over, when it is engaged again?
    In other words.. once the car takes over.. is that the same as disengaging
    the EV and it stays disengaged until you reactivate it?
    ...Or does it allow the batt to get so charged and then it takes over again?

    thanks.
     
    #9 windstrings, Dec 5, 2005
  10. rogerSC

    rogerSC Member

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    I've also noticed the reluctance of the car to go into "EV" mode sometimes with a green battery, everything apparently warmed up, and at less than 40MPH. I'm not sure why the ICE should be running at all, but I kind of figure the car must know what it's doing, which is a less frustrating way to think of it. Kind of like multiprocessing in an operating system where it has to do things that only make sense to its own programming, doing things that I'm not currently aware need to be done.

    -Roger
     
    #10 rogerSC, Dec 5, 2005
  11. efusco

    efusco Moderator Emeritus
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    Once it disengages (manually or by the ECU) the only way to reengage is by hitting the button again.
     
    #11 efusco, Dec 5, 2005
  12. efusco

    efusco Moderator Emeritus
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    This is completely normal. Getting the battery into the green range should never be a goal. The ECU actually works very hard to avoid that condition though it's allowed when extra charging is available.

    Remember that the ECU is focused on keeping the ICE within it's most efficient operating range...the true determinant of overall MPG. If it feels a little more 'juice' is needed to maintain speed or power it'll take a little from the battery, then it may send some back when it can...it's all happening very quickly and is totally normal and far more efficient than you could possibly do it manually.

    Take a look at all the info at John1701a.com He really coveres this stuff pretty well.
     
    #12 efusco, Dec 5, 2005
  13. hdrygas

    hdrygas New Member

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    When I am in the green zone, if I can, I turn on the EV mode until I get down to the blue zone. After that I get back in to hybrid mode by goosing it for a second. I get into the green more often in the winter, than the summer.
     
    #13 hdrygas, Dec 6, 2005
  14. Uncle GroOve

    Uncle GroOve New Member

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    4 days later....


    5.9L / 100 KM avg. and still learning :)
    Still feel that some fine tune tweaks could be the name of the game.
    looking forward to some mega-hack remote unit :D
     
    #14 Uncle GroOve, Dec 7, 2005
  15. Tideland Prius

    Tideland Prius Moderator of the North
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    Not bad. What are the temps like right now?
     
    #15 Tideland Prius, Dec 7, 2005
  16. Uncle GroOve

    Uncle GroOve New Member

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    Uh-oh.... lost you there...
    Temps here are like 2-4 below zero (celsius).

    I probably need to address the issue w/ the cold intake air (block the radiator grille? doesn't sound good to me) and would also like to try out the block heater thing (is it available on EU models??).

    Best...
     
    #16 Uncle GroOve, Dec 20, 2005
  17. jimgraffam

    jimgraffam New Member

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    After 5 weeks w/ my Prius, I've hit all green for the first and second times in the past week in normal driving conditions in 20 deg F weather. By the time I get back onto local streets, I can usually bleed it down over the last mile into the parking lot in EV mode.

    I can also often get much of the way back to the highway on EV. I figure why not if I'm starting to see higher battery charges in colder weather.

    Is this not adviseable? And should I expect this trend to reverse in summer?
     
    #17 jimgraffam, Dec 21, 2005
  18. windstrings

    windstrings Certified Prius Breeder

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    Do you feel using this technique gives you an overall better mpg per tank than not?
     
    #18 windstrings, Dec 21, 2005
  19. Parson

    Parson New Member

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    Hi. Just got my 05 Salsa Red three weeks ago.
    Took a trip yesterday and decided to check mileage. After the car was warm for a few trips around town, I filled up to make a trip of 200 miles. Temperature ran from 30 F to 25 F during the course of the trip. Started in daylight with lights in the on position during all driving.
    I ran the first 100 miles to my destination at 60 MPH. The car reported about 46 MPG at the end of the first leg.
    On the return home I dropped the speed to 55 MPH. The final MPG was 48.3.
    When I filled the tank, I put in 4.0 gallons ... for a real-time average of 50 MPG.

    I'm impressed. Can't wait for spring and summer!
     
    #19 Parson, Dec 30, 2005
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