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How to calculate Range Loss %

Discussion in 'Model S' started by Tribaltech, Jan 8, 2017.

  1. Tribaltech

    Tribaltech Member

    Joined:
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    Location:
    Michigan
    Hi everyone,

    Happy new year!! I am having a major senior moment and I need some mathematical help. I am typically one of those who is really good at math and physics but perhaps its the state of affairs in the world or a nasty head cold that I, for the life of me, cannot assess what is the accurate formula to calculate the range loss/gain %. Can someone please help me?

    Here's the scenario:

    Lets say I start with 200 miles of rated range that my Model S computer is showing as soon as I remove the charger. I drive 50 actual miles but the range I am left with is 130 miles instead of 150 miles. In this case what is your range loss %. Can someone kindly tell me the accurate formula to be used for this?

    I know this is all sorts of dumb but like I said I feel like half my brain has fallen off and I need help staying accurate. Thank you very kindly!
     
  2. kort677

    kort677 Active Member

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    florida.
    you need to understand the causes of the range loss before you can calculate an exact number. speed, climatic conditions and changes in elevation are the biggest reasons for range loss. the "ideal" range numbers are calculated at around 55 mph. driving faster than that, say 65+ mph as many people do results in a 5-10% loss of range. upgrades, cold weather, rain or snow and headwinds also take a significant toll on your range.
    the more you drive your car the better "feel" you'll get for the real range of your car based on your driving habits.
     
  3. arubinst

    arubinst Member

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    Hi,

    I think that would be 100 - (Real Miles)/(Estimated Miles) x 100

    In your case: 100 - 130/150 x 100 = 13.33 %

    Here's a way to test it. You were supposed to get 150 miles range, but you got 13.33% less than that.

    150 - 150*13.33/100 = 130

    Does this make sense to anyone else?

    Cheers,
    Abraham
     
    • Helpful x 1
  4. Tribaltech

    Tribaltech Member

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    I understand all of that. How ambient temps, driving speed, wind speed (head or tail), payload, etc. etc. factors into range loss. My question was strictly math related.
     
  5. Tribaltech

    Tribaltech Member

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    Perfect! I think it makes sense. I had the same calculation noted in a file where I track all of this. But all of a sudden I had a major brain fa*t and felt like all of mathematics had been erased from my brain. Thanks a ton for confirming.
     
  6. kort677

    kort677 Active Member

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    my answer was that there is no way to make a precise calculation since the variables are different every time you drive.
     
  7. CHG-ON

    CHG-ON Still in love after all these miles

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    I get the math, I think. But if I used 20 extra miles to go 50, I would go 20/50=40% more miles to get there.

    But I'm a finance guy and we all know that they can't addf worth a damn!:D
     
  8. tandrup

    tandrup Member

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    Location:
    Santa Rosa, CA
    The calculation in the examples above calculates how efficient your driving is compared to what the car uses to calculate rated range - but IMHO that is not what I would describe or define as the car's "range loss". When I hear "range loss", I think of how much range I have lost due to battery degradation and that's another story altogether. In the example above you cannot conclude that your battery has degraded by 13.3%.
     
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