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Has anyone else seen recent improvements in efficiency?

Discussion in 'Model S: Driving Dynamics' started by electrish, Oct 10, 2015.

  1. electrish

    electrish I Sing the Body Electric

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    #1 electrish, Oct 10, 2015
    Last edited: Oct 10, 2015
    During my commute to work, I have been trying to improve my efficiency, but have never really been able to drop consumption below 300-315 Wh/mi.
    Maybe it's the hilly terrain around here, but I've always felt that there even was a measurable penalty driving carefully in Insane mode vs. Sport, and I always have Range mode enabled.

    Lately, however, I've noticed a remarkable improvement, as I can now get into the 290 Wh/mi range, even in Insane mode, with Range mode on.
    For the first time ever, I've been able to beat the rated range.
    I am on 2.5.85, my P85D has a staggered 21" setup and my lifetime average over 10,000 miles has been 370 Wh/mi since I got the car in December 2014.

    Have there been any recent improvements in torque sleep and has anyone else noticed any change?
    Maybe it's just the favorable temperatures?
     
  2. pgiralt

    pgiralt Active Member

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    It's just the temperature. Range around this time of year is usually very good for me because of the mild temperatures.
     
  3. electrish

    electrish I Sing the Body Electric

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    Thanks for confirming my pessimistic premonition.
    I figured this improvement either happens right before something breaks or before the 450+ Wh/mi winter onslaught!
    However, I don't remember noticing a similar improvement in efficiency in the spring!

    It's interesting that the Tesla website's Range per Charge section doesn't reflect this effect of outside temperature, as they report improved range all the way to 110 degrees.
     
  4. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    That's actually been my experience. The warmer it is, the more efficiency I see. Especially on trips. Warm air is thinner and so there is less aerodynamic resistance. Just ask any pilot about the runway length for takeoff required in hot vs. cold weather. A/C doesn't use a lot of power, so it's a minimal factor--except in stop and go traffic which is always hard on efficiency.
     
  5. Cyclone

    Cyclone Active Member

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    Exactly. In Charlotte, I'm now average 310 instead of 330 Wh/mi.

    - - - Updated - - -

    I presume you mean A/C in general. My big energy improvements have been once it cooled down enough that the A/C isn't trying to cool down a 130 degree cabin. 15 minutes later it doesn't use much energy, but those first few minutes are above 900 Wh/mi.
     
  6. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    Try using the A/C this way (works great for me in Texas):

    1. When possible park with the windows cracked a bit and the pano at 20% (the vent setting is useless because there is no cross flow). This keeps the car close to ambient temperature.

    2. Use Auto with no manual overrides and Range Mode off.

    3. When you first start the car, turn the temperature up to 26 or so (ideally no more than two fan blades "on"). The air will still feel cool but the amount of energy used will be far less.

    4. After the initial cool down period, lower the temperature by 0.5 degrees.

    5. Repeat as you start to become uncomfortably warm, keep reducing temperature by 0.5 degrees.
     
  7. Cyclone

    Cyclone Active Member

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    Thanks Jerry. It's not a problem now and even during the summer, I would just precool the car via the app five minutes before walking down. I can't leave things cracked because of rain. I tend to walk up to my car's puddle. :)
     
  8. sorka

    sorka Active Member

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    I average about 280 wh / mile on my 260 mile round trip commute in 70 to 80 degree weather at 70 MPH. 19" wheels air on lowest setting (P85D).

    The S60 loaner I just had couldn't crack under 300 wh / mile on the same commute.
     
  9. electrish

    electrish I Sing the Body Electric

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    Wow, I've never been able to get down to 280, especially not during the summer's hot 90s, when I averaged in the 320-330s.
    This would go against hotter temperatures improving the battery's efficiency.

    Unless Tesla changed something recently about torque sleep ....
     
  10. David99

    David99 Active Member

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    Air might be adding in, but I think the battery definitely is more efficient at higher temperatures.
     
  11. sorka

    sorka Active Member

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    Came to respond to a post I saw in email but it's been deleted.

    Model S efficiency is related to air temperature regardless of whether cabin heat or air is used. Also, 100F temperatures with AC is about as efficient as 80F weather is without AC. The decrease in air density more than compensates for the increased energy use to run the compressor. My wh / mile at 70 MPH in 100F with AC is about 275.
     
  12. brec

    brec Member

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    The warmer it is, the more runway is required for takeoff. Turbofan (jet) engines, propellers and ICEs, and airfoils (wings) all work better in colder -- denser -- air.
     

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