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Auto-pilot uses more battery than a real driver driving efficiently?

Discussion in 'Australia & New Zealand' started by EcoCloudIT, Apr 26, 2016.

  1. EcoCloudIT

    EcoCloudIT Member

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    Just drove (for the first time) 1.5 hours on the high way, stop and start type of traffic for much of it, and the car averaged 200. However when I do this drive I am usually at around 165 for the same type of conditions.

    Would this suggest the car is less efficient at spotting a impending slow down therefore gets less time on re-gen that a proactive driver and/or takes off much quicker than I do when speeding back up to the set cruise speed?

    I dare say if travelling at a constant 100km/h it would make no difference.

    How does everyone else find it?

    -ECIT
     
  2. lennier

    lennier Member

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    I think on highway cruising it's at least as good if not better than a human, but any situation like the one you describe where more traffic-awareness and prediction is involved it will do worse. It never knows that it's not worth accelerating at the normal rate etc because you're about to stop again, it can only react. That said unless you need the efficiency the convenience of letting it handle things is generally worth the tradeoff I think except where the stop/start is at higher speed and its late reactions can get stressful.
     
  3. Bangor Bob

    Bangor Bob Member

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    Holding a constant speed is inefficient unless you're driving on a flat, featureless plain. As soon as elevation changes (even small ones) come into the picture, varying speeds are more efficient and cruise (and autopilot) doesn't do that.
     
  4. PJF000

    PJF000 TOCA Member

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    I've thought the same. When driving on AP and approaching roundabouts, the car stays at programmed speed until it approaches cars slowing for the roundabout then breaks hard. (not much regen). If I deactivate AP knowing a roundabout is looming, then I get regen and brakes are hardly used. I inevitably exit the roundabout at approx the same time for either. In those instances manual is better than AP. Same would apply for a variety of similar scenarios.
    At the moment, the sensors don't have the computing ability of the eye/brain, but I am sure that will change over time.
     
  5. Cosmacelf

    Cosmacelf Active Member

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    Yes, you can tell it is more inefficient. It accelerates more quickly and brakes harder than a human does in even moderately heavy traffic. And it doesn't look beyond the car ahead of it, nor does it read the brake lights of the car ahead of it, it is only processing the car's distance.

    Having said that, AP is still really worth it. Much less tiring driving with AP than without it.
     
  6. ICUDoc

    ICUDoc Member

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    Whilst I agree that it brakes later and harder than I do, I am almost always struck by the fact that it uses less energy than I do...
     
  7. lennier

    lennier Member

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    @bangor: Constant speed is less efficient in the absence of regen (and so energy is wasted to heat on downhill stretches) but I believe tests of the Model S have shown TACC do to at least as well if not better than human drivers in highway driving. Unless you're hypermiling no-one wants to slow down up hills to conserve energy anyway.
     
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  8. newtman

    newtman Member

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    I was under the impression Autopilot was explicitly not designed for situations with cross traffic (intersections and roundabouts).
     
  9. brianman

    brianman Burrito Founder

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    Links please. I doubt the assumption for such tests.

    Tesla's CC is currently not (IMO) at all designed as an efficiency tool. It's designed as feature parity with the past. Hopefully in the future, they'll focus on efficiency with some knobs for the driver to adjust.

    Efficiency Miser Mode
     
  10. newtman

    newtman Member

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    There's a relevant anecdotal thread here: Auto-Pilot Efficiency better than manual driving | Tesla Motors

    TL;DR if you're an aggressive driver TACC will be more efficient, otherwise your mileage may vary.
     
  11. PJF000

    PJF000 TOCA Member

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    You mean you don't activate AP, close your eyes and hold your breath before entering a roundabout/intersection?
     
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  12. TesAus

    TesAus Member

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    Maybe it doesn't try to race the other cars away from each stoplight? ;-)
     
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  13. raynewman

    raynewman Member

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    Yeah - that's a problem; isn't it?
     
  14. ICUDoc

    ICUDoc Member

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    Twice a week. Max.
    And, as you know, it's not a race......
     
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  15. jerjozwik

    jerjozwik Member

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    the one thing i have found that helps with stop and go aggressive braking is the car distance setting. first time i used TACC it was set to one car lengh, turned out to be a very uncomfortable drive home in traffic. next day i set it to two, was much smoother as the car has more time to use regen and not having to smash the electro brakes. ive tried 3 car lengths but that just invites people to cut into your lane and triggers the aggro braking.
     
  16. mspohr

    mspohr Active Member

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    I've settled on 7 (max) as my distance. Much smoother operation of the car. Yes, people do cut in front but it's safer and I am not an agro driver so I'm OK with it.
     
  17. mspohr

    mspohr Active Member

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    Is rapid acceleration less efficient? Yes, it uses more energy but for a shorter period of time to get to speed.
     
  18. jerjozwik

    jerjozwik Member

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    los angeles, it does things to a man...
     
  19. mspohr

    mspohr Active Member

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    Fortunately, I don't drive in heavy freeway traffic often but when I have, I've found that AutoPilot does a great job of making it much less stressful (especially start and stop traffic).
    I think it would be an interesting experiment for you to try setting AP to distance 7 in your daily rat race commute and see what it does to you stress level. (You'll have to get used to people pulling in front of you... just don't let it bother you. I've noticed that people who pull in front usually don't spend much time there; they quickly leave for another "better" lane.)
     
  20. garyjac

    garyjac Member

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    AP much better at conserving energy on the highway. TACC on its own is about the same in traffic. Just my 2 cents.

    P.S. If you observe the "lane jumpers" closely, it is usual to catch up to them in a traffic light or two. The urban traffic control systems we have are deliberately designed to nail cars to 50 kph average in the main and they do a very good job of that.
     

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