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Affect of Cold Weather and the Heater on EV Range

Discussion in 'Prime Main Forum (2017-2022)' started by TonyPSchaefer, Mar 3, 2019.

  1. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
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    I just posted a video of how cold weather and running heater affect the EV Range in my Prime. You all know me; you know I wouldn't post a hateful video attacking the car that I've been driving for more than 14 years (Prius family). So here's the secret: It's a total reverse hit job. People are going to think that it's attacking the Prime but it ends up stating what we all know around here: the Prime is a really good car.

    To be honest, I didn't know how the whole thing was going to end but I knew that my mileage is not dramatically diminished in cold temps. So I hooked up my cameras and drove to work. On the way in, I ran the heater and reported on the EV range. On the way back - just to mix it up - I drove without the heater. I had to rely on distance plus estimated range remaining because my commute isn't far enough to fully deplete the battery.

    So how did it turn out?
    Driving in: 28 degrees F. Drove 18.3 miles, estimated total range 25.2 miles.
    Driving out: 33 degrees F. Drove 18.3 miles, estimated total range 31.4 miles.

    Like I said, not even I saw that coming. Check out the video here:

     
  2. PT Guy

    PT Guy Senior Member

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    The bun warmers and heated steering wheel are resistance heaters, so they draw down the battery somewhat when used. Switch them off when not needed. Note the driver's-side pilot light for the passenger's heated seat.
     
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  3. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
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    At first I thought the passenger heater indicator light was a little silly until I dropped off a buddy and saw that his warmer was still on. Then I understood.

    Of course, it doesn’t explain why they are placed in such awkward spots to begin with.
     
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  4. bisco

    bisco cookie crumbler

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    still awkward? i thought they improved from pip
     
  5. Tideland Prius

    Tideland Prius Moderator of the North
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    Great video. As long as it doesn’t get too cold where you live (say below 15°F), you’ll see close to 22-25 miles with eco driving habits. Once the temps get close to 50°F as a daytime high, I see the range creep up to 27 miles. I saw the rated distance as high as 31 miles but didn’t actually drive 31 miles to see if it checked out.

    Psst. It’s “effect”.
     
  6. Old Bear

    Old Bear Senior Member

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    Excellent video and reasonably consistent with my experience.

    It's worth noting that he started out with the Prime having been in a modestly heated garage. That helps. And possibly he used the cabin pre-conditioning function which I have found really helpful. (If the cabin is pre-warmed, you can go quite a while before the interior starts to feel cold.)

    Also, the effect of running the heat-pump in the Prime is not linear. When you turn it on with the cabin cold, it will use a lot of energy to bring the cabin up to whatever temperature you've set. But once the cabin is at temperature, the heat-pump will cruise along and not be as demanding of the traction battery.

    The use of energy for propulsion versus its use for heating are two different problems. Possibly, in the future, automotive designers might come up with a heating system which uses gasoline or propane in a catalytic heater like one of those Coleman camp heaters. This would be more efficient than running all the moving parts of an ICE just to generate heat or using battery power. Sure, it burns some fossil fuel, but most people don't wear goose-down jackets and wear earmuffs in their houses and don't want to wear them just to drive their cars.

    (Some of us may be just old enough to recall automobile ads which boasted of "R/H" -- radio and heater -- because many base model cars did not include these features until the 1950s.)

    car-heater.jpg motor-robes.jpg
     
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  7. jb in NE

    jb in NE Senior Member

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    In the 2019 Prius (don't know about the Prime), the seat heater switches move to the center console near the cup holders. Perhaps the Prime for 2019 will have this change as well.
     
  8. 3PriusMike

    3PriusMike Prius owner since 2000, Tesla M3 2018

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    It would be interesting to try the same experiment by reverse when the heat is used. Also interesting to know the elevation difference...since even slight drops can improve mileage a lot. My commute is around 8 miles and I get much better MPGe in my PIP and Model 3 going to work compared to returning. The elevation difference is only ~180 ft...or 22 ft per mile

    Mike
     
  9. Tideland Prius

    Tideland Prius Moderator of the North
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    2020 you mean. The 2019 Prime is at (some) dealers.