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Self-Selected Torque-Sleep

Discussion in 'Model S: Driving Dynamics' started by chriSharek, Jan 14, 2016.

  1. chriSharek

    chriSharek Member

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    How hard would it be to add a feature for the driver to be able to turn on and off the torque-sleep for the (I think) rear motor? By only using one of the motors, wouldn't that improve efficiency (but sacrifice performance)?

    I akin this to my wife's 2004 Jeep Wrangler. It's in 2WD all the time - saving gas. If we need it, we put it in 4WD, but normally remains in 2WD. My Jeep SRT8, on the other hand, was all-wheel-drive all the time - thus getting the whopping 11 MPG.

    The logic seems to lead to the ability to turn off one of the motors if you're heading on a long trip, or just want to save the range. What am i missing?
     
  2. tstafford

    tstafford Member

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    Maybe having both working but at less amounts is more efficient than having one working hard?
     
  3. rns-e

    rns-e Member

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    Read this: Let the hacking begin... (Model S parts on the bench)

    WK057 documented awd vs 2wd on a P85D with and without range mode
     
  4. chriSharek

    chriSharek Member

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    Thanks for the link. I'll continue to scrub through the 56 pages of conversation . . . this is what I dislike about this forum. I understand there's a search function - and have used it - but never find answers to my specific questions.
     
  5. SabrToothSqrl

    SabrToothSqrl Active Member

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    nope. the single motor model S uses more power per mile. you'd be packing the dead weight of a 2nd motor.

    your ICE uses less fuel in 2WD as it has less spinning parts and less moving mass, making the car move. My last.. 3 wranglers however, in 2 or 4WD use the exact same # of spinning parts.. fuel milage be damned, I need grip! (you don't want to leave it in 4WD on road)...

    I'm guessing (and don't have proof) but if I was building the AWD S, I'd make the front motor use a higher gear ratio. such that during acceleration you rely mostly on the rear motor 0-30 and then use the front motor more 30-60

    that way you can selectively select the most efficient way to get electrons to the ground. and obviously if you need GO power, you throw power at both motors.

    the biggest benefit to the front motor (other than AWD) is that I suspect it enables almost an electronic transmission. of course I could be wrong, but that's how I'd have built it.

    I also considered 'self selecting' the Active Fuel Management (4 vs 8 cylinder) in my Tahoe... nope, just let the computer decide. it can do it 1.6 billion times faster than you can...
     
  6. chriSharek

    chriSharek Member

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    Thanks for the response. Still not sure my initial question has been answered. Seems that if you REALLY wanted to squeeze out just a little more range, you should be able to turn off one of the motors - manually.
     
  7. Andyw2100

    Andyw2100 Well-Known Member

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    You're assuming the car isn't already maximizing efficiency.

    According to what Tesla has said about torque sleep, the car automatically allows one of the engines to sleep, calling upon it as needed, with no perceptible delay. We know that we get the greatest torque sleep benefits with range mode on. There is no reason to believe that we can give up any more power in exchange for any additional efficiency. In theory, Tesla has already taken care of that.

    Here's the relevant blog post: Driving Range for the Model S Family | Tesla Motors
     
  8. spottyq

    spottyq Member

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    Like Andyw2100 said.

    Actually, even with range mode off, you only use one motor (except for short periods of time, when starting from a stop or requiring large amounts of power.)
    Source

    Also, from what I've read on other forum from electric / hybrid cars who displays more information than Tesla, they are only a a few very limited cases where the driver is actually more intelligent than the car in determining how to save energy. Assuming Tesla does not want to show us more information, it is a good idea to only let the user tell the car how aggressive it must be with energy saving.
     
  9. RDoc

    RDoc S85D

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    I've never understood what torque sleep had to do with range mode. AFAIK there are no downsides or even perceptible differences between torque sleep on and off, at least I've never noticed any. However, with range mode on the heating and AC is significantly limited.

    Why not just have torque sleep on all the time?
     
  10. Todd Burch

    Todd Burch Electron Pilot

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    Tesla already does this automatically. If you're not demanding a lot of power (say you're in cruise on the highway), one motor is shut off.
     
  11. Andyw2100

    Andyw2100 Well-Known Member

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    As per Jerome Guillen, there are some benefits of Torque Sleep realized with range mode off, but more Torque Sleep benefits are realized with range mode on:

    Firmware 6.1 - Page 109

     
  12. chriSharek

    chriSharek Member

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    Thanks to everyone for the informative responses. Again, I'm coming from a Volt that I've got to eek out every electric mile. Hope, and expect, that won't be the case with MS.

    Thanks again.
     
  13. Whitmarsh

    Whitmarsh Member

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    I agree; most of the time, I find general answers or answers that have nothing to do with what I searched for. also, I have not found a way of searching a particular thread rather than a whole forum.

    - - - Updated - - -

    I hope they'll update this to include the 70s - it's overdue, I feel.
     
  14. MikeBur

    MikeBur ManualPilot

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    There's a LOT of content generated and finding the wheat from the proverbial chaff is challenging, yes

    I believe the search box on the top of every page is just a google subsite search, so you can get pretty fancy if you like, eg
    range AND mode AND manual AND torque, though the advanced search button gives many more options

    or use your favorite search engine with the subsite contained within, eg "range AND mode AND manual AND torque sleep AND DATE RANGE:01012015 AND (site:teslamotorsclub.com OR site:teslamotors.com)" (without the quotes ;-))

    if you're finding a lot of meaningless results, then filter them out using negative terms, eg -bed

    hope this helps
     

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