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Concern Over Increasing Wh/Mile

Discussion in 'Model S: Battery & Charging' started by bancroftc, May 11, 2016.

  1. bancroftc

    bancroftc Member

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    Austin, TX
    So I'm a little puzzled by a recent spike in Wh/mile in my 85D. I took delivery in Oct 2015 and have maintained a pretty consistent Wh/mi over the past 5,000 miles, usually hovering in the 300 range. My lifetime is 345 wh/mi and most of my driving is around the city with not a ton of freeway driving. On road trips I've had no issue keeping it at or below 300. However, in the past 30 or so days, my 30-mile trailing Wh/mi has been floating around the mid/upper-400 range which I have never seen before. In fact, previously I had to try HARD (with a TON of spirited driving) to even get my Wh/mi to hit 400 and now I'm there every single day, and I even saw 500 for the first time ever this week.

    I have been making a concerted effort to drive very conservatively just to see how low I can get my efficiency, but I can't get it below 400. Previously this exercise would have me in the high 200's no problem. And I'm starting to get concerned because everything I know about efficiency and Wh/mile is that it should be decreasing as the weather warms up, not increasing significantly.

    Two things have changed that are worth noting:

    -I moved offices so have a slightly different commute route.
    -Weather temps have increased into 80's/90's.
    -Due to the above, running AC a little harder, usually around 68 degrees full Auto then up to 70 once cooled off. I have been pre-conditioning my car more frequently than before. I do notice an annoying vibration/buzzing that I can feel (slightly) in the floor/steering wheel from the AC when the fan runs up and the temp is low. This is on my list for the next service, but aside from that it seems to work great.

    I checked EVTripplanner for my current commute, and with the above conditions even with a speed multiplier of say 1.1 it says I should be in the high 200 range. Like I said, even with a feather foot I can't out of the 400's right now. Am I missing something here, or do I have cause for concern such that I should be reaching out to Tesla service? All systems seem to be just fine in the car. I'm on 19" cyclones and tire pressure is around 45psi as of last night (same as it's been since I took delivery).

    Any thoughts or suggestions would be very much appreciated!

    Thanks




     
  2. jerjozwik

    jerjozwik Member

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    im surprised im getting the same wh/mi as you, p90d.

    341 lifetime [almost 4,000 miles], lowest was daily 262.
     
  3. thimel

    thimel Member

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    That does sound concerning. Can you do a test drive of your old commute without AC to make sure it is a change in the car and not one of those two things? If your commute is short, only a few miles, I could imagine your preconditioning doing this. Otherwise, it is hard to think of where all that energy could be going.
     
  4. bancroftc

    bancroftc Member

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    Yeah I will definitely try this out, and I will also try my current commute without AC as well to see if that might be the culprit. I'll try Range mode as well to see if that helps.

    Does pre-conditioning factor into the Wh/Mi calculation? I would tend to think not since there is no driving occurring.

    My rated range has been stable at 241 @ 90% so I'm not seeing any fall off in rated miles/capacity.
     
  5. JanetM

    JanetM Member

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    My rated Wh/M ratings have been fairly stable at about 300 since I've had the car. Then yesterday, when I got in the car, I noticed it had jumped to over 400. Looking at the energy app I could see that during the look-back period that would correspond to my previous drive (an uneventful trip to get groceries) the energy app registered a period of usage that spiked up to nearly 900 Wh/Mi and hovered about there for a few miles!! This can't be accurate data, obviously. Came here curious to see if anyone else has seen something similar in their energy app.
     
    • Love x 1
  6. robby

    robby Member

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    Have your trips been short? Climate often runs very heavily for the first few minutes the car runs, then energy consumption drops. But on short trips you may not drive long enough to see the drop, and so the high numbers accumulate. My lifetime average is about 339 (but more like 295 if you discount winter driving), but I can easily get stuck in the mid-400s when this happens.

    Range mode limits climate control -- you could try turning that on (or turning climate off completely) to see if it helps -- just so you can pinpoint where the consumption is.
     
  7. eye.surgeon

    eye.surgeon Member

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    Check your tires for an abnormal wear pattern. It's possible alignment could be off. My wh/mile usually goes down, not up, in the summer. The biggest variable, however, is your right foot.
     
  8. woof

    woof Model S #P683 Blue 85 kWh

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    Wind speed can have a profound effect.
     
  9. gavine

    gavine Petrol Head turned EV Enthusiast

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    When the car is stopped at a light, how many kW are you using (see usage meter on dash)? If a lot, then something is running in the background. If low, then the high usage could be drivetrain related or seized brake calipers.
     
    • Informative x 1
  10. pdx4s

    pdx4s Member

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    post 7.0 my P85 has jumped from 280wh/m range to 340-400/wh/m on the same daily commute route. Confirmed also on my nightly charge duration is now extended by 20mins vs before 10/15 (7.0 install). I also felt small vibration at times when stopped (AC off), suspect algorithm used to turn on the battery cooling pump works harder post 7.0 or something similar. Asked TM to look at the log files several times but they have done nothing yet in that respect, feels like degradation in their responses to this specific issue and not happy with them.
     
  11. bancroftc

    bancroftc Member

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    So I've done a bunch of experimenting on this issue since I made the original post - and all I can tell is that's it most likely due to my new shorter, slightly hilly commute, probably combined with the AC working harder to cool the car in the now hotter weather. I've also got some AC concerns that I'm going to have service look at that could be contributing as well. I appreciate all of the feedback.
     
  12. gavine

    gavine Petrol Head turned EV Enthusiast

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    Make sure you use recirc with the AC. That makes a difference.
     
  13. bancroftc

    bancroftc Member

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    On that note, is there any way to tell what mode the circulation is in when you have in Auto? I will try keeping it on recirc though.
     
  14. jerry33

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

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    Auto is heavily weighted towards recirc. This is fine in summer, but in winter it tends to fog up the car.
     
  15. Johan

    Johan Took a TSLA bear test. Came back negative.

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    You did check tires both for uneven wear as well as exact pressures? I like to keep them close to 50 psi, at least 48.
     
    • Like x 1
  16. syosh

    syosh Member

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    Wasn't there a software update pushed out recently? Maybe the calculation method changed?
     
  17. StaceyS

    StaceyS Member

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    If you are pre-conditioning the car without it being plugged in, it will show a higher wh/mile since last charge.
     

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