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2023 Prime around town - EV mode or Auto HV/EV?

Discussion in 'Gen 5 Prius Technical Discussion' started by tovli, Jul 17, 2023.

  1. tovli

    tovli 2023 Prius Prime replaced 09 Prius

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    XSE
    After reading:

    and another article that panned the whole PHEV concept, (along with a few BEV fan-boys panning the HEV concept as well), I am wondering about my plan to use EV mode around town, and HV mode on the highway.

    Toyota has tuned the Auto HV/EV mode for minimum energy consumption, but they don't know my cost of recharging, nor my cost of refueling so they cannot drive for minimum cost to the car's owner.

    I'm going to have to determine what my gas MPG is in Auto HV/EV mode, which is much more complicated than MPG in HV mode.
     
    #1 tovli, Jul 17, 2023
  2. Marine Ray

    Marine Ray Senior Member

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    I used to try and game the EV vs HV thing, then...:)

    relax.png
     
    #2 Marine Ray, Jul 18, 2023
    Tideland Prius, tovli and AndersOne like this.
  3. Trollbait

    Trollbait It's a D&D thing

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    First, the article being quoted was about Toyota hybrids, not the PHEVs. The EV mode being discussed isn't one that is powered by a charge from an outlet. It is a low speed mode Toyota installed back on the gen1 to move the car out of the garage to get the lawnmower out without the engine firing up, and to not disturb the neighbors with engine noise when leaving and returning home.

    For most people, it is just gimmick. It is possible to use the EV mode to improve the hybrid's fuel economy. More likely, it will result in use of EV mode making it worse. What mostly happens is the driver gets the timing of using it wrong, or simply over uses it. The car them ends up burning extra gas getting the battery charge back up to where the system is happy. The inclusion of the useless EV ratio display on a hybrid doesn't help.

    Repeat, this has nothing to do with the Prime.

    As for the Prime, EV Auto doesn't know how long it will be before you charge the car again. It is just going to use up the grid charge for best efficiency and system health regardless of whether that charge gets used up or not on the trip. If you know your errands will take you beyond what EV mode can cover, go ahead and use HV on the highway. Save the battery charge for when it will net the most miles.
     
    #3 Trollbait, Jul 18, 2023
    tovli likes this.
  4. tovli

    tovli 2023 Prius Prime replaced 09 Prius

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    What confuses me most about the decision is Toyota choosing 84 mph to force switch from EV to HV mode. Is that the point gas becomes more energy efficient?
     
    #4 tovli, Jul 18, 2023
  5. tovli

    tovli 2023 Prius Prime replaced 09 Prius

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    Location:
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    Vehicle:
    2023 Prius Prime
    Model:
    XSE
    I'm no hyper-miler, but I am the hyper-curious type cursed with a not-very-quiet question stream inside my head which I can rarely ignore. I am not interested in my ECO Score, nor am I willing to piss off the idiots behind me to maximize my miles/kWh. I do like to have an approximate model for complex systems, and test the quality of my model.

    I do just get in my Prius Prime and drive. The over thinking comes later, when I get home. I thought retiring would help me relax - it turns out work was a useful distraction.
     
    #5 tovli, Jul 18, 2023
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  6. Trollbait

    Trollbait It's a D&D thing

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    It was chosen by engineering limits and marketing. The max motor outputs with the drive train gearing sets the limit for the max speed possible. The marketing comes in with buyers wanting a 'full' EV experience. That is minimal time the engine is on. If the goal was to maximize overall efficiency of electricity and gasoline, the engine would come on sooner.
     
    #6 Trollbait, Jul 18, 2023
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