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Model S miles/kWh

Discussion in 'Model S' started by efusco, Dec 28, 2011.

  1. efusco

    efusco Moderator - Model S & X forums

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    #1 efusco, Dec 28, 2011
    Last edited: Dec 28, 2011
    Over at PriusChat | Toyota Prius Forums, News, and Accessories someone asked about miles/kWh for various vehicles (actually they asked about kWh/mile), but we did a bit of calculation for the Model S that I thought members here would like to see.

    160mi/40kWh = 4.00 mi/kWh = 0.250 kWh/mi = 0.155 kWh/km
    230mi/60kWh = 3.83 mi/kWh = 0.261 kWh/mi = 0.162 kWh/km
    300mi/85kWh = 3.53 mi/kWh = 0.283 kWh/mi = 0.176 kWh/km
    320mi/85kWh = 3.76 mi/kWh = 0.266 kWh/mi = 0.165 kWh/km
    *

    Perhaps those differences aren't dramatic, and we also don't know how accurate the range forecast numbers really are, but it seems that the smaller/lighter battery packs will make a significant differenced in efficiency. Also, that the improved aerodynamics of the Performance version really have a positive impact.

    *At 55mph per numbers from Tesla
     
  2. surfingslovak

    surfingslovak Member

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    Neat idea! Please keep in mind that the kWh numbers Tesla provides likely correspond to the rated full capacity of the pack. The usable capacity will be dialed down a bit, for the sake of battery longevity. The ratio of usable to total capacity could be anywhere between 75% to 95%. I would recommend using 85% for your calculation. This would yield between 4.2 to 4.7 miles per kWh, depending on trim and battery size. The 4.7 mpk number is quite good for a large sedan traveling 55 mph.
     
  3. GSP

    GSP Member

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    Good points. Also don't forget that these data are mi/kWh from the battery. These are useful to judge how far you can drive before recharging.

    EPA ratings (at fueleconomy.gov) are mi/kWh from the wall. These are the kWh that should be used to calculate energy costs.

    GSP
     
  4. daxz

    daxz Member

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    I used the Roadster's efficiency curves and estimated out the Model S's range per speed:
    attachment.php?attachmentid=3789&d=1325103158.png
     

    Attached Files:

  5. widodh

    widodh Model S R231 EU

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    Nice!

    At 130km/h (81mph) I should be able to drive about 300km on a 85kWh battery, that is very nice!
     
  6. Zextraterrestrial

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    Don't forget to include what speed you need to be traveling for this

    I'm sure it wouldn't be that hard to make a curve, I saw someone had an eq with the drag and other resistances factored in another recent thread



    oh, you said 55 already but anyways, it would be nice for other speeds too

    'The 4.7 mpk number is quite good for a large sedan traveling 55 mph.'
     

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