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EV mode + highway speed = terrible acceleration

Discussion in 'Prime Main Forum (2017-2022)' started by Mike in NH, Feb 16, 2017.

  1. Mike in NH

    Mike in NH Junior Member

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    I was driving to work today on an eight-lane divided highway. In default EV mode, doing 65 - 70 in the third lane and pulled into the fourth lane to pass the car ahead of me. Put my foot down on the throttle and no acceleration!

    I had expected reasonable acceleration and a switch to gas mode with the large change in throttle position, but that did not occur.

    To me, this is a design flaw in the drive-by-wire throttle algorithms. With my old 2013 Prius Four in EV mode, a significant throttle change would kick in the gas engine immediately, combined with a message about leaving EV mode due to "excessive acceleration".

    Has anyone else noticed this?? This could be a real problem in an emergency situation.

    - Mike
     
  2. dalcon95

    dalcon95 Senior Member

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    You may need to drive in EV auto mode. It should kick the engine on when you need the extra power.

    Posted via the PriusChat mobile app.
     
  3. Mike in NH

    Mike in NH Junior Member

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    Thanks. I was using the defaults for power and mode....
     
  4. dalcon95

    dalcon95 Senior Member

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    You can put it in EV mode until you know ahead of time that you need power and then switch to EV auto mode. Then when you are done, switch back.

    Posted via the PriusChat mobile app.
     
  5. Optimus PRIME

    Optimus PRIME Active Member

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    Definitely need EV AUTO mode for ICE boosted power. Or maybe try POWER mode instead of the default Normal mode.

    I have tested out ECO mode, where it feels like the gas pedal needs 2x power to get the same speed as in Normal mode. However, I have not tried POWER mode much.
     
    Toyota4Life and dalcon95 like this.
  6. Tideland Prius

    Tideland Prius Moderator of the North
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    You need to be in EV Auto on the highway.
     
  7. bwilson4web

    bwilson4web BMW i3 and Model 3

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    This fits with my 'seat of pants' understanding of the three modes:
    • EV - +199.9 MPG - nothing but electrical with a smooth transition as MG1+MG2 work like a single motor. Traction battery drain is proportional to distance at a fixed speed on level ground. Typically segments of 10-20 miles around town, I've done 301 miles over seven days.
    • EV Auto - +100 MPG - sustain speed in EV but enables ICE as needed for higher loads so traction battery drain is reduced but continues to decline. What I don't understand is if the EV portion has any relationship to the traction battery charge by some linear or nonlinear relationship. Less than 10 miles as the EV drain in a hilly area appeared to be going down faster than desired.
    • HV - 55-60 MPG - after warm-up, the engine runs in charge sustainment mode. About 1,200+ miles of seat time.
    • Charge Mode (untested) - <55 MPG - the engine runs at high power modes to put a charge on battery for future EV operation.
    Is this about how it works?

    My thinking is I need to run a week in each mode. I've already done a week in EV, 301 miles, so no need to repeat that test. In a month I'll know how well each one works.

    Bob Wilson
     
    #7 bwilson4web, Feb 17, 2017
    Last edited: Feb 17, 2017
  8. mr88cet

    mr88cet Senior Member

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    As others have replied, you're probably looking for EV Auto mode.

    I guess I'll admit that I personally am a pretty grandmotherly driver- usually not driving at high speeds or high accelerations, and usually not taking risky lane changes and such. I'm hoping pure EV mode will work for me most of the time, once my P.Prime comes in, but I guess I'll see...
     
    #8 mr88cet, Feb 17, 2017
    Last edited: Feb 17, 2017
  9. yoyoman

    yoyoman Active Member

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    This is one of my xmas wish list. I wish my ev mode toggle button is built on the steering wheel. Maybe somewhere close to the LKA button... :)

    So since this is my xmas wish list, it's probably not going to happen.. :-(



    iPhone ?
     
  10. Lee Jay

    Lee Jay Senior Member

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    It should have taken you 2.5 seconds to go from 65 to 69 and 6.9 seconds to go from 65 to 76, without the ICE and with dual motor NOT working.

    That's not all that bad, but it will be very smooth so you will feel very little.
     
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  11. EspressoFueled

    EspressoFueled Junior Member

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    This is precisely the reason why I want the option to change the default to EV Auto or simply have the Prime save drive mode settings of HV, EV, or EV Auto when power cycled. As it is, now I have to remember to hit EV Auto each time I drive away after charging.

    I made a thread on this here, but sadly no one replied back with good news: Any way to get EV Auto to stick after power cycle? | PriusChat
     
  12. bisco

    bisco cookie crumbler

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    because good news is in short supply these days...
     
  13. vvillovv

    vvillovv Senior Member

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    When did this happen? Can you duplicate the problem?
    If you can make it happen again - what are your EV mode stats when it happens?
    ie:
    EV miles available at start of trip
    EV miles available when problem shows up
    MPH range you trigger the problem
    Ambient temps
    A/C or Heat on with temp and mode settings
    Any other switchable accessories on

    Toyota may already know about it,
    but they also may not know about yet.
     
  14. bisco

    bisco cookie crumbler

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    february 16, 2017
     
  15. Washingtonian

    Washingtonian Senior Member

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    I set mine on both EV Mode and Power Mode a couple of years ago and have been driving with that since then. Last time I added gasoline was in March, so I doubt that it has effected the efficiency of the car. I have no problem passing on the freeway.
     
  16. bisco

    bisco cookie crumbler

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    i need a model 3
     
  17. PT Guy

    PT Guy Senior Member

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    "maybe try POWER mode instead of the default Normal mode"
    These are equal at both 0% accelerator pedal and 100% (floorboarded).

    Just leave it in EV Auto for the whole drive. The engine will come on only when it is needed. Use the PWR mode if you like the quicker response---but there isn't any additional power.