When to use Eco mode?

Discussion in 'Gen III 2010+ Prius Fuel Economy' started by kaze72, Aug 17, 2012.

  1. kaze72

    kaze72 New Member

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    Hi,

    I've been driving an 2007 Prius unitl last week, when I upgraded to an 2010 model. I'm very happy with it so far.

    My question is however, when to use the Eco mode? I think it is pretty efficient in Normal mode. When does the Eco mode give me additional fuel savings? Is it design for any specific driving conditions?
     
  2. stream

    stream Senior Member

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    I never use ECO mode anymore. When I first got my Prius (my first hybrid), I decided to drive in ECO mode as default. Then a few members here posted how they were getting better MPG in "normal" mode than ECO, so I turned ECO off, and guess what--my MPG increase modestly ( a few MPG). No more ECO for me.

    There's info on the differences in the various modes in the owners manual (basically throttle sensitivity mapping and A/C settings, as I recall), and a bunch of threads here--a search will get you lots of info if you're interested.
     
  3. Corwyn

    Corwyn Energy Curmudgeon

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    The car is no more or less efficient in Eco mode (except for running the AC a bit lower). The driver may be more efficient in Eco mode. By adjusting the response of the car to gas pedal, it makes it easier for the driver to perform some hypermiling techniques (like gliding and accelerating in the proper range). Eco mode makes the gas pedal more sensitive at small depressions, (and, of course, correspondingly less sensitive at large depressions). Power mode is the opposite. Normal is in between. Full power is available in all modes, should it be needed.
     
  4. john1701a

    john1701a Prius Guru

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    Watch what ECO mode does in the winter.

    ECO lowers the coolant threshold from 145°F down to 114°F.

    The result is the engine staying off longer, resulting in higher MPG.
     
  5. kaze72

    kaze72 New Member

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    Thanks for all your interesting answers. I think I will use Eco mode when driving in slow and very dense traffic.
     
  6. Corwyn

    Corwyn Energy Curmudgeon

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    In order to truly get an idea about which mode one gets better MPG in, one should do an A-B-A test. That is, use one mode, switch, and then switch back, compare all three results. Otherwise, one can miss an unrelated change (like weather, or one's improving driving skills)
     
    sfv41901 and F8L like this.
  7. szgabor

    szgabor Active Member

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    Never heard this before ... do you have some reference for this ???

    I do not like ECO mode I am less efficient with it and is harder in city driving ... but will start in ECO if this can be confirmed ... my commute starts out in local street with lights and stop signs so it would make a difference !!!
     
  8. john1701a

    john1701a Prius Guru

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    My blogs are loaded with real-world observations. We got pretty excited with the upgrade from Iconic to +2010, knowing the new ECO feature targeted thermal thresholds in addition to throttle play.
     
  9. GasperG

    GasperG Active Member

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    But in winter you would normally use heater, and the engine will run until cabin temperature is meet or coolant temperature is high enough to provide that heat. In winter (when no defrost is needed) I start to drive with ventilation off, and when ICE reaches its temperature then I turn it on, but even then in slow traffic ICE comes on just to provide cabin heat.

    So does this threshold for coolant temperature include heater on?
     
  10. walter Lee

    walter Lee Hypermiling Padawan

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    Why would ECO mode do this in the winter time but not the summer time? o_O
     
  11. john1701a

    john1701a Prius Guru

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    Yup. It extends the engine-off time, which is great considering how much slower winter traffic can be.


    It does then too. Coolant temperature isn't the only criteria though. The other is how fast the vehicle is moving. Watch the "green" zone on the Eco-Meter; exceeding that into the "white" starts the engine.
     
  12. rpg51

    rpg51 Member

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    This is where I draw the line. I like to be warm in the cold northern winters.
     
  13. retired4999

    retired4999 Prius driver since 2005

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    +1 Mine stays in ECO always, Thanks John! It will stay warm in eco mode no problem.
     
  14. rpg51

    rpg51 Member

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    Could someone explain this a little more? I don't understand what is meant by thermal thresholds. Also, in cold winter climate, what impact does it have on cabin temperature. My big concern is keeping the windshield and windows warm enough to avoid fogging.
     
  15. F8L

    F8L Protecting Habitat & AG Lands

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  16. Mendel Leisk

    Mendel Leisk Senior Member

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    The main thing I disliked about ECO was the gas pedal travel: too much for my taste. I got tired of having to push further, further, to get a reaction. It's unfortunate, because there likely are other benefits, but that was the deal breaker.

    I just leave it in normal, I think it makes little or no difference to the bottom line mpg.