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Dual motor efficiency

Discussion in 'Model 3' started by LectrikPower, May 7, 2016.

  1. LectrikPower

    LectrikPower Member

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    So in pondering my option choices I am leaning heavily towards single motor for my MIII. I would rather spend the money on SC, AP and cold weather packages.

    Other than the obvious traction and performance enhancements that AWD gives, is there an efficiency difference between RWD and AWR for a tesla? Is it better to run a single motor at a higher workload or two at lower? I think I remember something about the front motor not being used during highway driving on AWD S's?

    My apologies if this has been covered to death. I did search the forum first and mostly got threads on TSLA stock. Thanks:)
     
  2. Craig9080

    Craig9080 Member

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    70% of braking force is generated by the front axle. With a single motor M3 you will be wasting all of this as heat on a traditional brake disk, with a D you will be able to recoup some of it. Also, the regen will be much better as it will feel a lot more like traditional braking as opposed to a [not-so] gentle E-brake tug. I'm sure the Model S owners can chime in as to actual numbers.
     
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  3. mspohr

    mspohr Active Member

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    With the model S, the dual motor versions are about 5% more efficient. A small improvement but if you also consider the better handling and performance, it could tip the scales for you.
     
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  4. Jason Bourne

    Jason Bourne Member

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    IIRC, in a dual motor Tesla, each motor has different performance and efficiency curves. For example, the front motor is better at top speed but the rear motor is better at acceleration - so the software leverages those benefits in management operations of the car (this is just an example and possibly not factually correct, but this concept is my point).
     
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  5. JeffK

    JeffK Active Member

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    For Wisconsin and anywhere that snows I'd recommend AWD for safety's sake. If it's less than $5K extra and you have at minimum a year and a half to save for it, I'd say try to make it work.

    Sure you can get by with RWD, but why? Do you plan on anyone else driving it?
     
  6. DFibRL8R

    DFibRL8R Member

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    The regen braking with a single motor is pretty robust even for a car as heavy as the Model S. I have a single motor and I rarely use my friction brakes (really just emergency braking and upon final approach to a stop the last few yards). Thus I don't see the additional motor having a great benefit in terms of efficiencies in braking in typical use. The improvements come in with power output where there is a more efficient use of 2 motors in tandem than a single motor (something about torque, sleep etc, I'm not an EE so I'll leave the technical particulars to someone else!)
     
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  7. LectrikPower

    LectrikPower Member

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    I can see how that would work with software computing best efficiency. Thanks.
     
  8. LectrikPower

    LectrikPower Member

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    Yes, my wife will be driving it as well. She is an excellent driver:)
    For reference, my 02 Mazda Protege5 was the only car we had for a few years. Granted it was front wheel drive but it has no ABS or traction control and a manual transmission. She commuted 40 minutes each way year round rain sleet and blizzard and did great. I'm not saying it was ideal but she is a pro. Our Kia Serento is front wheel drive but it is an SUV and has ABS and decent traction control? Obviously AWD would be better but I'm not convinced it is totally necessary.

    I will have to see what the final price difference will be if I go with the D. Like I said I would rather spend the money on the other options. Maybe I can have it all, we shall see.
     
  9. e-fit

    e-fit Member

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    Has anyone compared the Telsa S AWD vs RWD? I currently drive an i3 and the one thing I don't like is that when you are using regen, and come into a tight corner, the regen can reduce or stop altogether (especially in the wet) to prevent the rear wheels dragging. For me just that on its own is enough to want me to go AWD, thought I'd want to check it will actually do what I want first!
     
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  10. Mkorpal

    Mkorpal Member

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    Based on what what Tesla states on their website for the S, duel motors adds 6 miles of EPA range, and reduces 0-60 times by 0.3 seconds. Not to mention better handling. Considering Tesla is charging 3 grand for a 15 mile increase in range, and we know the duel motor on the 3 will be less than 5 grand (I think it will be 4 grand most likely), I'd venture to say that duel motors will be the most no-brainer option on this car.
     
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  11. Kandiru

    Kandiru Member

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    Given your geographical location dual motor is the only safe choice. Coming from Quattro I can confidently say the Model S AWD is excellent, mixed with Michelin X-Ice X-Green low rolling resistance (less energy use) tires winters are a breeze here in Ohio.
     
  12. Garlan Garner

    Garlan Garner Active Member

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    Whatever Ludacris comes with....that's what I'm getting.

    I suppose that would be Dual Motor. right?
     
  13. jerry33

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

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    Note that the efficiency gain is for highway travel. Stop and start driving will be less efficient. Frunk space is also lost. Either of these may or may not be important to you.
     
  14. Zoomit

    Zoomit Part 3 Awaiter

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    That's certainly the case with the S/X, but not a given with the 3. They may opt to have a single frunk size and leave the RWD cars with unused volume between the axles.

    Having said that, it does look like the frunk could expand rearward based on this picture.
    [​IMG]
     
  15. Garlan Garner

    Garlan Garner Active Member

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    You guys really care about frunk space?
     
  16. Zoomit

    Zoomit Part 3 Awaiter

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    I don't know. I've never had a car with one. It might be easier to store and get to certain items from the frunk than the trunk.
     
  17. jerry33

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

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    When I go on trips, I just lay my pants and shirts and their hangers down in the frunk. The small items go in a bag. No suitcase necessary and I only need to take the bag, shirt, and pants into the room where I'm staying. So yes, I care about frunk space.
     
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  18. Garlan Garner

    Garlan Garner Active Member

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    lol - If its so close of a trip....lay your stuff down on the back seat.
     
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  19. LectrikPower

    LectrikPower Member

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    Well I don't know about "only safe choice" but I know it would be better:)
     
  20. jkk_

    jkk_ Member

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    I've seen reports that with the "facelifted" S the frunk space is also lost for RWD cars. Apparently the space is reserved for the HEPA-filter even if you don't have it.
     
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