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Optimal speed for max ev range

Discussion in 'Prime Fuel Economy & EV Range' started by lochnersm, Oct 29, 2020.

  1. lochnersm

    lochnersm Junior Member

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    Hi all. I'm hoping to collect enough data to put together a scatter plot chart. I suspect optimal speed to maximize ev range will be around 25 mph similar to tesla, but I haven't seen anything confirming that. Please help by providing battery usage, distance and average speed.

    So reset your trips. If you can provide approx outside temp for your trip also, I can probably split that out as well.

    Remember: I'm looking for battery USAGE not battery remaining. At the very least, signify you gave me remaining battery so I can subtract it from 100 to calculate your usage.

    Thanks!

    Posted via the PriusChat mobile app.
     
  2. Salamander_King

    Salamander_King Senior Member

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    I am not sure the data that can be reported by many PP drivers on the battery usage, distance and average speed will give you what you want.

    Say for example:
    1. Drive 40 miles in 60 min in non-stop steady motion on very flat terrain all in EV using 100% of SoC, that would be 100% battery usage, 40 miles EV range at 40mph, which is very doable.
    2. Drive mostly uphill with a lot of stop and go traffic and took the same 60 min to drive all on EV and used up 100% of SoC to go only 25 miles, again very likely scenario. But this would be 100% battery usage, 25 miles EV range at 25mph.
    3. Drive down a very long hill (started at the top of a big mountain), you go free rolling at 60mph with very little stopping for 60 miles mostly down hill all in EV and you used only 20% of SoC. So you will have a data point of 20% battery usage, 60 miles EV range at 60mph, again this is very doable in certain driving situation.

    Furthermore, for each of data point, there are other variables to consider: temperature, road surface conditions, wind direction and speed, load in the vehicle, tire inflation and make of tire used, etc, etc... Do you see my point? There are too many variables to consider.

    Unless the data are from the same car on the same road with the same (or at the least similar) driving condition, you are not going to find meaningful result. And even in ideal testing condition, the result suggests the optimal speed for the maximum EV range only for that testing condition. It may not apply to any other driving conditions. As the mpg is different for each drive, it is the case of "YMMV". That being said, I am sure in general, everything else being equal, slower you drive more EV range you can obtain from the same kWh of battery charge.
     
    #2 Salamander_King, Oct 29, 2020
    Last edited: Oct 29, 2020
    Hicksite likes this.
  3. lochnersm

    lochnersm Junior Member

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    Yes, there are a lot of variables to consider. I'm hopeful that with enough input, it will average itself out, i.e. for every uphill drive there will be a downhill drive to even it out. Maybe I'm wrong...

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  4. MTN

    MTN Active Member

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    Most efficient is usually prior to air resistance becoming significant.
    25 mph sounds right, you know, +/- 15 mph ;)

    Also what will you do with this data? Drive 25 mph all the time?
    Inflate your tires a bit more than the door placard, remove excess items (weight) and drive smoothly. Now you're optimized.
     
    jerrymildred likes this.
  5. Tideland Prius

    Tideland Prius Moderator of the North
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    I don't have data but I suspect 40km/h is also a sweet spot for the Prime.


    You may want to clarify and ask for the Drive Monitor information which will give average speed.

    Most people think that the speed they travel is the average speed.
     
    Rmay635703 likes this.
  6. lochnersm

    lochnersm Junior Member

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    Yes, I'm using drive monitor. It seems I may be the only one interested in this information so I'm just going to use my info everyday and see how it looks.

    Posted via the PriusChat mobile app.
     
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  7. vvillovv

    vvillovv Senior Member

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    I believe I'm safe saying - even if it sounds like a broken record to some here at PC- you're not the only one interested in getting optimal EV range from the Prime.
    Although what is optimal and how optimal is determined is often due mainly to the conditions we drive in
    which vary widely - and the style of driving we most often use.
     
  8. Rmay635703

    Rmay635703 Senior Member

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    18mph no stops if your not using heat Or climate controls, below that switching losses outpace aero gains, above that aero losses trump switching losses

    “terreign” will affect the needed speed since losses grow when you open the throttle at low speed, meaning a higher goal speed DWL is needed if things aren’t flat
     
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  9. sam spade 2

    sam spade 2 Senior Member

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    Broad averages like that are usually pretty meaningless.
    In this case, the biggest factor is WIND resistance......so the aerodynamics of a specific model, or even each individual car, would be important to reach any meaningful conclusion.
    So would wind speed.
    And the fuel being used should make little to no difference as far as the most efficient speed goes.