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EV Auto or HV mode for long drives?

Discussion in 'Prime Fuel Economy & EV Range' started by PrimeOwner_CA, Jan 27, 2017.

  1. PrimeOwner_CA

    PrimeOwner_CA Junior Member

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    Just curious which would be better to optimize mileage. On a trip from LA to SF, I noticed that with a full battery in HV mode, the battery usage was minimal and the ICE was being used a lot. After 100 miles the battery was near full charge. Switching to EV Auto quickly depleted the battery. I don't recall exact distances but I would guess in less than 50 miles the battery went down to the HV-only mode.
     
  2. Trollbait

    Trollbait It's a D&D thing

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    If the trip is by highway or freeway, best thing to do is use EV until you get to the highway, then switch to HV. Once you are withing the remaining EV range of the destination, go back to EV.
     
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  3. mr88cet

    mr88cet Senior Member

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    My understanding is that HV mode is effectively a "battery hold" mode, meaning that it it is intended to keep your battery charge about the same while it's in that mode.

    I've been thinking that, independent of fuel economy, the best bet for a long trip is to charge up your battery and then take your long trip in HV mode. The advantage is that, if something entirely limited to the ICE (say spark or fuel injection) the should fail, you could still use EV mode to get you to the next repair shop, or at least hotel.

    I should clarify that I'm partly speculating here, in that, if a failure limited to ICE operation should occur, there's still no guarantee that they won't just throw in the towel and shut down the entire drive system, or put it into "limp-home mode," so to speak, even if the failure has no effect upon its ability to function in EV mode.
     
    #3 mr88cet, Jan 27, 2017
    Last edited: Jan 27, 2017
  4. bisco

    bisco cookie crumbler

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    'switching to ev auto quickly depleted the battery'. this is a very interesting report, compared to the 'ev auto' thread.
    mr88cet is correct, if you drive hv, it won't use much of the wall charge. maybe 10% or so.
     
  5. Db17

    Db17 Member

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    Somebody correct me if I'm wrong, but why would anybody believe they could outthink the computer that makes the decisions in EV mode? Unless you are making short enough trips to stay well within the limitations of running on the battery only including AC and heating when you run out of battery, you're out. Does it really matter where and how you use it?

    For me, the biggest advantage of driving this care is the huge reduction in my stress level. I prefer to just let the car do it's thing. Between the fantastic headlight system, the radar assisted cruse control, the backup cross traffic warnings ... I haven't had to yell at another motorist for weeks.

    YMMV. ;)
     
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  6. giora

    giora Senior Member

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    Why?
    EV auto is still EV driving unless there is a very high power demand, and return to EV afterwards.
     
  7. bisco

    bisco cookie crumbler

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    wouldn't ev mode do the same? that has been the complaint, if you press too hard on the pedal.
     
  8. Optimus PRIME

    Optimus PRIME Active Member

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    EV Auto kicks into ICE when high speed is needed. EV mode kicks into ICE a lot sooner and more often based on my driving.
     
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  9. mr88cet

    mr88cet Senior Member

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    Humans, and the driver in particular, know a little more about the future than the computer. You, for example, know that your entire trip will fit into one EV charge, after which you'll recharge, so there's no need burn any gas in order to preserve battery power. You know that the next 5 miles will be slow and go, so there's no benefit to keeping the engine warm. So forth...
     
  10. bisco

    bisco cookie crumbler

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    this is interesting. so ev auto keeps the ice off more than ev?
     
  11. giora

    giora Senior Member

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    My understanding is that usually ICE will not start in EV mode even when you floor the pedal (unless over max speed or some other extreme conditions like very low EV charge).
     
  12. bisco

    bisco cookie crumbler

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    and yet, we have post #8.
     
  13. giora

    giora Senior Member

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    I would think just the opposite.
     
  14. bisco

    bisco cookie crumbler

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    i know, right? but this car is confounding.
     
  15. giora

    giora Senior Member

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    Post #8 is in total contradiction to the manual and to what Danny and all the reporters test drives, so maybe it is not the car that is confusing:confused:
     
  16. bisco

    bisco cookie crumbler

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    [shrug] ? we have a lot of learning to do, and prime owners are not that interested.
     
  17. giora

    giora Senior Member

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    Well let us hope not all of them.

    As for your test drive, I found this in the manual:
    Also, if a little electricity is remaining in the hybrid battery (traction battery), HV mode is automatically selected.
    Page 84.
    I read 'little electricity' as low EV miles (say 1-3 or so).
     
  18. bisco

    bisco cookie crumbler

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    sounds right.
     
  19. MikeDee

    MikeDee Senior Member

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    That's what I've ever been doing since I'm avoiding plugging in. The EV miles stay right up there too, when I drive in HV mode.
     
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  20. Trollbait

    Trollbait It's a D&D thing

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    For the same reason a person can use less gas than cruise control. The car doesn't know the route ahead, and is reacting to changes that could be better handled in by being proactive. Take an upcoming climb. The best way to approach it for efficiency is to speed up and build momentum before starting the climb, and then let that speed bleed off while going up. Cruise control will wait until the car starts losing speed on the climb, and then 'floor' acceleration.

    When taking trips longer than the Primes EV range, the car will go through the grid charge first before turning on the ICE for the rest of the trip. The driver can turn the ICE on portions of higher steady speeds, like the highway, and end up driving more miles total on grid charge.

    If you prefer to leave it all to the car, cool.
     
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