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Eco vs. Normal: HV vs. EV

Discussion in 'Prime Fuel Economy & EV Range' started by mr88cet, May 26, 2019.

  1. mr88cet

    mr88cet Senior Member

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    A couple of other folks and I seem to have independently concluded that Eco vs. Normal mode doesn’t seem to make a lot of difference to EV range. I’ve more or less switched over to Normal mode since we all made that observation.

    However, I recently took a road trip — 200 miles each way, so ran out of battery pretty quickly. Soooo, had to do some bumper-to-bumper, stop-and-go traffic in HV mode. I concluded that, unlike in EV mode, Eco was considerably more economical than Normal in the usage!

    More specifically, I found that it was considerably quicker to fire up the ICE even on the relatively mild accelerations of stop&go traffic, and that it tended to keep the engine on for a considerably larger percentage of the time as a whole.
     
    #1 mr88cet, May 26, 2019
    Last edited: May 26, 2019
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  2. jb in NE

    jb in NE Senior Member

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    Which mode in HV was doing this?
     
  3. mr88cet

    mr88cet Senior Member

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    Normal mode seems to be considerably quicker to fire up the ICE than Eco, and overall runs it for a larger percentage of the time.

    In HV Eco mode, bumper-to-bumper traffic, I’d eyeball estimate that the ICE is off around 3/4 of the time. In Normal, it’s off ... probably closer to 40-50% of the time.
     
    #3 mr88cet, May 26, 2019
    Last edited: May 26, 2019
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  4. schja01

    schja01 One of very few in Chicagoland

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    I noticed the same thing in my friend's Conventional Gen 4 Prius.
    That is, in Normal Mode the ICE runs substantially more of the time than in ECO mode.
    On as aside I've been running State Farm's "Drive Safe and Save" monitor.
    Currently I save about 30% on my car insurance.
    Things it "dings" you are are Fast Acceleration, Fast Stops, Fast Turns etc.
    It will show you when you are speeding (more than 8 mph over the limit) but it's not a "ding"
    unless you go over 80 mph.
    I found even in ECO mode it's difficult to keep from getting a demerit for Fast Acceleration. It takes
    concentration especially if the limit is 25 mph.
    FWIW.
    J
     
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  5. bisco

    bisco cookie crumbler

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    is eco anything more than throttle mapping in prime?
     
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  6. mr88cet

    mr88cet Senior Member

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    Best I can tell, it’s pretty much just a mundane throttle re-mapping in the case of EV mode. However, it seems to have more-involved ramifications in the case of HV mode, specifically along the lines I described.
     
  7. bisco

    bisco cookie crumbler

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    could it just be that it's easier to not call for the engine because eco requires so much foot pressure?
     
  8. mr88cet

    mr88cet Senior Member

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    The scenarios I saw here — the first time in stop&go traffic in HV Normal mode (previously only in Eco) — were of this nature:
    1. Bumper-to-bumper stop-and-go traffic,
    2. DRCC set for, typically 45MPH, although obviously very rare getting anywhere near that,
    3. Each time the car in front of me creeped ahead, I tapped the gas to prod DRCC to creep up behind the car ahead of me and stop again.

    To get the car moving again, yes, sometimes I would hold the accelerator down for longer than “just a tap,” but, Eco or Normal, it was barely cracked open at all, and the acceleration was about the same, notably ”rather small.”

    However, in Normal mode, I found it much more likely to kick in the ICE than in Eco mode, and slower to shut it off after it did.
     
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  9. bisco

    bisco cookie crumbler

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    almost like it is trying to maintain a higher temperature
     
  10. mr88cet

    mr88cet Senior Member

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    Perhaps...
     
  11. bisco

    bisco cookie crumbler

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    but eco doesn't suppress hvac in gen 4/prime, correct?
     
  12. mr88cet

    mr88cet Senior Member

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    Not sure what you mean by suppressing HVAC.

    Eco mode, by default, turns on Eco mode for the HVAC system, but you can switch it either way in Eco, Normal, or Power modes.
     
  13. bisco

    bisco cookie crumbler

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    in gen3, there's no switch. so eco automatically suppresses hvac. in doing so, the engine has a lower coolant range, and comes on less and for shorter periods of time.

    if you have it switched off, that kills my theory.
     
  14. mr88cet

    mr88cet Senior Member

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    In this trip, I had two bouts with such stop-and-go traffic, first in Normal mode (going to) and the second in Eco (going back). In both cases, the AC was on, set at 78, IIRC. The outdoor temperatures were pretty comparable: mid-upper 80s.
     
  15. Salamander_King

    Salamander_King Senior Member

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    On different thread, I was testing PRIME's capability to preserve EV SOC when driven exclusively under HV mode. Then, I noticed that although PRIME loses a bit of SOC at start-up and EV drives even on HV mode, regenerative braking used under HV is sufficient to recoup all of lost SOC, thus I was able to bring back SOC from starting at 91% back to a full charge 100% under HV mode.
    MPG in Hybrid Mode | Page 6 | PriusChat

    Turns out when I did this I had changed my usual ECO mode to NORMAL mode inadvertently and did not notice the change. I have not tested the regenerative capability under ECO mode yet, but it is true that under NORMAL mode in HV, the car was much easier to get out of EV and start the ICE. I usually drive to maximize EV range, but if you are trying to regen the SOC without using CHARGE mode and want to recharge all the way to 100% SOC, NORMAL mode maybe the way to drive.

     
    #15 Salamander_King, May 28, 2019
    Last edited: May 28, 2019
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  16. jb in NE

    jb in NE Senior Member

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    I tested regen in EV in both ECO and NORMAL modes, flat stretch of road, 2 ways to eliminate wind, etc. Zero difference in regen noted between the two modes.
     
  17. Salamander_King

    Salamander_King Senior Member

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    There may not be any quantitative differences in those two modes. My thinking is that under NORMAL mode, it is much easier to get out of EV range and accelerate the car into the RED zone and then coast in EV to charge. I have not tried this under ECO mode, but I think I would have to push much harder to get out of EV zone due to lower throttle response. This qualitative difference makes NORMAL mode much easier to manipulate the the regen result one wants out of the car. Let me test this hypothesis on my way home today.;)
     
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  18. melliehens

    melliehens New Member

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    If I am going to the city, I keep it in EV mode until I reach the interstate, then switch to HV once I get up to speed. That way, I have EV miles to use in the city or in traffic. If I am just driving in town, I obviously keep it in EV mode, same with the state highway where I go 50mph or less.
     
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  19. Gokhan

    Gokhan Senior Member

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    I seem to be getting around 70 mpg in the ECO mode in HV driving -- both city and highway -- if I'm gentle on both pedals. Does this sound about right?
     
  20. Tideland Prius

    Tideland Prius Moderator of the North
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    Yup. I’m around 65mpg on the highway and mid 70s in the city.

    closer to 60mpg if I’m driving in the middle of the day with traffic and over hilly terrain.