Idle vs Shutdown

Discussion in 'Gen 3 Prius Fuel Economy' started by roddomi, Apr 21, 2012.

  1. roddomi

    roddomi New Member

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    According to some site:

    The reason: if you shut down your Prius, it will go thru a startup cycles that consumes more gas. Is this true?

    Thank you,

    Rod
     
  2. F8L

    F8L Protecting Habitat & AG Lands

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    True but would you want to leave your car running without you in it? Theft, lawsuits ohh my! :)
     
  3. roddomi

    roddomi New Member

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    That was going to be my next question: is it possible to program the Prius so I can lock the car from the outside while idle? According to the User's Manual:

    "The door cannot be locked if the POWER switch is in ACCESSORY or ON mode, ..."

    Thank you,

    Rod
     
  4. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    I wonder if 'some site' (we are not allowed to actually look at) is reporting about Gen 1 or 2, and you are trying to apply that to Gen 3 or c or v.
     
  5. krazypriuslady

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    I let mine be in idle when I have to pull out of the garage and get my lawnmower etc out then put the car back in.
    Mostly because. I'm afraid I'll get the engine knock by not letting it go thru all the stages. Otherwise I'd have powered off like I would,do a regular car
     
  6. szgabor

    szgabor Active Member

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    This is not true at all .... if your "car" is upto temp and the stop is short and the external temp is not too cold ... the car will NOT go through the warm up cycle !!!

    I regularly shut down even at red light IF the car would be running ONLY to charge the battery (like two or one bar !!) and the car will NOT go through the warm up cycle again ...

    But this is just my experience your maybe different ...

    I am monitoring with scangauge so I KNOW the temp and RPM etc...
     
  7. Britprius

    Britprius Senior Member

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    Does the US Prius not have an EV button to stop the warm up cycle for such situations.
     
  8. DetPrius

    DetPrius Active Member

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    It does but there are multiple operating conditions that can prevent EV mode that cannot be overridden.
     
  9. Corwyn

    Corwyn Energy Curmudgeon

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    I often let it idle if it hasn't completed the warmup cycle yet. While this seems logical to me, I don't have any data that it is better.
     
  10. mad-dog-one

    mad-dog-one Prius Enthusiast

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    That's the recommendation of Car_thiefs.com
     
  11. markabele

    markabele owner of PiP, then Leaf, then Model 3

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    So you are saying if my Prius has been sitting all night in a 40 F degree garage all night and I start it up in the morning that even if I hit the EV Mode button right away that it will still go through the warm up cycle? Just curious...new to the Prius world, but learning lots fast!
     
  12. Britprius

    Britprius Senior Member

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    I find that if I hit the EV button about 2 or 3seconds after the start button (before the ICE starts up and no matter what temperature) the car goes into EV mode and the ICE does not start.
     
  13. Sergio-PL

    Sergio-PL Member

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    Go throught Prius power stages. In S0... about 10 seconds from Ready you have the opportunity to enter EV mode if conditions are met (temp, state of charge... different in EU, US and Japan). S0 is not available in EU when below freezing.

    http://priuschat.com/forums/gen-iii...76501-gen3-warming-up-stages.html#post1068435
     
  14. fuzzy1

    fuzzy1 Senior Member

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    The U.S. market GenIII Prius will not go into EV at all if the engine coolant is below 68F. Above that is a wide temperature span where EV is limited to 9 mph.

    Non-US markets have a different EV temperature threshold. I seem to remember 32F / 0C, but other will have to give a definitive answer.
     
  15. walter Lee

    walter Lee Hypermiling Padawan

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    The startup cycle for the Prius uses a bit more fuel so that it has near zero emission levels. This can be minimized by keeping the engine warm (heated garage) or using an engine block heater (EBH).

    For a gen1 and gen3 Prius, turning the car off for more than 15 minutes wont consume more gas than if you left it on for 15 minutes - this is especially true if the outside temperature fairly warm. Prius will use the same or less gasoline to reheat the emission system.

    For a gen2 Prius with a Coolant Heat Storage (CHS) tank, turning
    off the car when waiting for more than 15 minutes will likely
    save you gasoline - because the gen2 Prius saves some of its coolant heat in a thermos bottle.
     
  16. Codyroo

    Codyroo Senior Member

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    Everytime I turn my car "off", when I restart it, I will go through some kind of warm up cycle. This does not mean the engine will start right away, but if I do fire up the engine, it will not shut off during a glide for at least a minute (if not 3 minutes).

    For example, this happened the other day. I always drive in ECO mode.

    1) It was 70F when I left work. I drove home (~50 minutes driving time) arrived home with the engine temperature at 190F, 6 bars on the SOC, outside temperature was 64F.

    2) I was in the house for <10 minutes and I got back into the car to go to my son's baseball game.

    3) Upon powering up, the engine did not start up (as expected) and the scangauge showed the engine temperature to be 172F.

    4) I glided down my hill to a stop sign. Upon accelerating away from the stop sign, I went into the second fat band and the ICE turned on. I accelerated to 25 mph and glided to the next stop sign. However, despite the engine temperature reading well above 170F (>77C), the engine was still running around 1080 rpms. My instant MPG reading went from >99 mpg (upon removing my foot from the gas) to ~75 mpg (as I initially glided) to ~50 mpg as I pulled up to the stop sign. Once at the stop sign, the engine turned off after I was stopped for a second.

    5) This process continued for the 1.25 miles to the baseball field. As I arrived at the field (3 minutes later) the car would finally go into a 0 RPM glide, but when I gently accelerated into the second power band again, the engine still ran (~1080 RPM) during the following glide.

    Engine temperature was near 190F by this point.
     
  17. jdcollins5

    jdcollins5 Senior Member

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    I would be careful with the shutting down approach at a stop light, especially if your HV battery is down to two bars and needs the ICE to run to recharge. When you turn the car off you are running only on your 12V battery without it being recharged. That is a good way to drain a 12V battery and premature failure.

    If your car is up to temp why would you not just let the car take care of its needs. If the ICE comes on during a stop light there is usually a pretty good reason that it needs to run.
     
  18. szgabor

    szgabor Active Member

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    Yes I am careful, I know that it will be a few minutes. If the car is turned off is turned off nothing running off the 12V battery (except the SKS at that moment).

    But if you think about what you are saying, we should not stop the car and park it etc if the HV battery is not OVER 2 bars ?? I am sure you do not think that either.

    The car is NOT aware of the life situation (that I am going to go in a minute and it will have plenty of spare time and ICE cycle to recharge) but I am the driver so I know.


    The Car doesn't really need to recharge the HV battery I know that the car doesn't. It is over protects the HV battery. If the 12V battery can not re-boot the car you would be dead at the next parking the car REGARDLESS of the HV status ...

    But of course you should use your car as you see fit ... I just shared my experience...
     
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