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Turning rear A/C off for better range?

Discussion in 'Model X: Battery & Charging' started by hiroshiy, Feb 4, 2017.

  1. hiroshiy

    hiroshiy Supporting Member

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    New to my X, delivery January 20th and was at the detailer's for full XPEL wrap and glass coating.

    Coming from Sig S P85, I'm pretty surprised to see high energy consumption of my X in the city (stop and go in Tokyo). Have 20 inch wheels and using sport mode (ludicrous turned off). I wonder if turning off rear A/C makes any difference.

    In theory it should reduce power usage but do you have any experiences or instrumented test results? Right now I turn it off when driving alone. With family I ask them and turn on if necessary.
     
  2. Tequesta

    Tequesta Member

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    Check your manual, but i believe that the back air conditioner, set for "Auto" only works when there is someone sitting in the back seats.
     
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  3. gjunky

    gjunky Waiting for the Model ☰

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    I don't think the rear AC makes a significant difference. With 9200 miles on our X so far, our avg consumption is 365/mile. Usage is a good mix of city streets and freeway. Perhaps that helps as a comparison.
     
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  4. Gwgan

    Gwgan Almost a wagon

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    True.
     
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  5. travwill

    travwill Active Member

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    It doesn't make much difference - A/C is nothing like heater use.

    With that said, if you have rear on Auto, it only comes on even if it detects weight in one of the back seats. You'll notice it says that no rear occupant are detected and its off without someone back there. You can force it on if you want at times, or force it off even.

    The X just eats up energy much more than the S. 350-400 is going to be your new norm in good conditions, sometimes you can achieve better at lower speeds closer to 300/320 its rated for, but not often. In Winter, kiss all that goodbye and say hello to 600+ if you are somewhere cold in not long drives...
     
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  6. goneskiian

    goneskiian Active Member

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    Check the Average Wh/m thread and others about this. 20" wheels are averaging 360, while folks with 22" wheels are averaging over 430 Wh/m.

    Here's the spreadsheet I'm using to track it...

    What's your 90% and Lifetime Wh/m

    Threads...

    Model X: Average Wh/mile Tracker

    Model X Energy Consumption
     
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  7. hiroshiy

    hiroshiy Supporting Member

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    Thank you all for the info. So I can set to auto and not worry about it. Didn't know that! I have a 10kg car seat (when not occupied) in the 2nd row - will it turn on the rear A/C??
     
  8. xkwizit

    xkwizit Member

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    It takes a few thousand miles before you settle into the 360-370 wh/m of course depending upon driving patterns and conditions. Something to do with break in on tires.
     
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  9. goneskiian

    goneskiian Active Member

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    Tires only take about 1000 miles to break in. The rest of those miles are just getting over how much fun all that instant torque is! :D:p;)
     
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  10. gjunky

    gjunky Waiting for the Model ☰

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    So very true. Never gets old though
     
  11. Cosmacelf

    Cosmacelf Active Member

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    It probably won't turn it on, but it is easy to check. When you are in the driver's seat, just reach behind your left side and feel if air is coming through the pillar vent. There will be no air there if AC is off. Personally, I like to keep rear AC NOT auto since if I had an infant back there, or in my case, a dog, I would always want AC to be on.
     
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  12. goneskiian

    goneskiian Active Member

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    No. It. Doesn't. :D:cool:
     
  13. hiroshiy

    hiroshiy Supporting Member

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    I actually have never tried to use Auto on rear A/C so I turned it on today. Now I found out that the A/C popup menu says "Rear A/C turned off because of no occupants". What a relief!
     
  14. Cosmacelf

    Cosmacelf Active Member

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    My software doesn't, or didn't, I'm not sure which, say that. Tesla probably added the warning at some point. I'm glad they did since it wasn't at all obvious what rear seat Auto setting does.
     
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  15. ptsagcy

    ptsagcy Member

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    No it won't because the front hvac handles the front and second rows. The rear unit handles only the third row.
     
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  16. hiroshiy

    hiroshiy Supporting Member

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    I have tested. With only a car seat in the 2nd row with no occupants in 2nd and 3rd, rear AC stopped. With one occupant in 2nd, rear AC was turned on.
     
  17. ptsagcy

    ptsagcy Member

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    #17 ptsagcy, Feb 16, 2017
    Last edited: Feb 16, 2017
    It doesn't seem to work that way in mine, but you can always play it safe and turn off the rear unit manually on the touch screen.
     
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  18. ohmman

    ohmman Maximum Plaid Member

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    Note that if anyone keeps seat belt extenders in the 2nd row for a car seat, those fool the car into thinking there are rear passengers even if the seats are empty. They also interfere with the easy entry features for the 3rd row as well as (sometimes) latching the 2nd row. Worth keeping in mind.
     
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  19. hiroshiy

    hiroshiy Supporting Member

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    @Cosmacelf , here's my screen showing that there are no rear occupants (the line at the bottom). DSC_6758-1080x1920.JPG
     

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