TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker or making a Paypal contribution here: paypal.me/SupportTMC

Autopilot question?

Discussion in 'Model X: Driving Dynamics' started by SSD420, Jun 4, 2016.

  1. SSD420

    SSD420 Member

    Joined:
    Mar 29, 2016
    Messages:
    854
    Location:
    ON, Canada
    Will the Model X speed while using autopilot? What speed limit will it drive at?

    Someone recently told me that it would go the speed of traffic around it. Is that true? Would love to learn more about autopilot before I take delivery on my 90D MX (fingers crossed) in mid July (hopefully sooner!)
     
    • Love x 1
  2. davidc18

    davidc18 Member

    Joined:
    Apr 25, 2015
    Messages:
    815
    Location:
    So. FL
    on the MS autopilot shuts off at 91mph. It will read speed limit signs but only limits speed to +5 mph on roads that it considers "restricted".
     
  3. Gwgan

    Gwgan Almost a wagon

    Joined:
    Aug 11, 2013
    Messages:
    944
    Location:
    Maine
    TACC (auto-speed) will maintain whatever speed you set but slow down for slower leading vehicles and maintain a speed-graded distance. Lane keeping (auto-steer) is unrestricted on highways but on lesser roads it limits the speed to 5mph over the known speed limit. Theoretical example, I have a range of speed limits on my commute from 25 to 55; I set TACC to 60 and as long as lane-keeping is active the auto-speed is good: slightly above the speed limit when able or slower in traffic.
     
  4. nctalkinghead

    nctalkinghead Member

    Joined:
    Dec 25, 2015
    Messages:
    110
    Location:
    Raleigh, NC
    Gwgan...does your TACC and active lane-keeping both increase and decrease your speed as you go thru the different zones?
     
  5. loganintx

    loganintx Member

    Joined:
    Mar 8, 2016
    Messages:
    592
    Location:
    Austin, TX
    TACC will not automatically adjust your set max cruise speed based on speed limit signs. You can however adust your current set max cruise speed based on the last sign read by pulling the stalk towards you and holding for about 1 sec. This will also take into account the mph offset you have configured in settings.
    These scenarios are for when TACC is disabled.
    If your car sees a 45mph sign and you are currently driving without TACC on at 30mph. If you pull the stalk towards you then TACC will be set at 45mph. If you were driving 50mph in the same 45mph zone and pull the stalk towards you then TACC will be set at your current speed of 50mph.
     
    • Informative x 1
  6. CHG-ON

    CHG-ON Still in love after all these miles

    Joined:
    Jun 24, 2014
    Messages:
    2,766
    Location:
    Santa Cruz Mountains, USA
    If you are using AutoPilot at say, 55, and the limit drops to 35, the car will slow down to the new limit, plus offset, and then speed back up when the limit rises. Very handy. That does not work when just in TACC. It will not go about your setting.
     
  7. FarmerDave

    FarmerDave Member

    Joined:
    Sep 3, 2015
    Messages:
    340
    Location:
    Martinsburg, PA
    I see that effect on smaller highways, but not on the Interstate.
     
    • Like x 1
  8. Gwgan

    Gwgan Almost a wagon

    Joined:
    Aug 11, 2013
    Messages:
    944
    Location:
    Maine
    As CHG-ON said, auto-speed adjust is only active with TACC + auto lane keeping, not TACC alone; there is no auto lane keeping without TACC.
     
  9. m2s2

    m2s2 Member

    Joined:
    May 22, 2014
    Messages:
    96
    Location:
    florida
    I will be doing a lot of highway driving. So if I have tacc and auto steer engaged, am I limited to speed limit +5 or 91 mph on most highways?
     
  10. brucet999

    brucet999 Active Member

    Joined:
    Mar 12, 2015
    Messages:
    1,316
    Location:
    Huntington Beach, CA
    There are bugs, though. I have noticed that the speed limit recognition algorithm is not smart enough to tell the difference between "Speed Limit 55" and "TRUCK speed limit 55" or "END speed limit 55". I have had to disengage auto steer in those cases to allow TACC to go to my set speed on secondary highways where AutoPilot limits speed to 5 over posted limit.

    And I also noticed on two lane winding highways, Auto Pilot will slow down for curves that are too sharp for the set speed; usually taking them at somewhat above the posted recommended speed. Very impressive.
     
    • Informative x 1
  11. vandacca

    vandacca Active Member

    Joined:
    Oct 13, 2014
    Messages:
    1,966
    Location:
    Hamilton
    I was impressed that the Speed Limit recognition knew the difference between "90 km/hr up ahead" and "90 km/hr begins". It ignored the former and paid attention to the latter.
     
    • Informative x 1
    • Like x 1
  12. brucet999

    brucet999 Active Member

    Joined:
    Mar 12, 2015
    Messages:
    1,316
    Location:
    Huntington Beach, CA
    AutoPilot is limited to 90 mph anywhere. Auto Pilot limits speed on secondary highways (non-divided, non-controlled access, in other words not freeways) to the posted speed limit plus 5mph, even when TACC speed is set higher.

    I wouldn't be concerned about no AP over 90mph. At that speed safety is a concern and your battery will be drained pretty fast.
     
    • Informative x 1
  13. m2s2

    m2s2 Member

    Joined:
    May 22, 2014
    Messages:
    96
    Location:
    florida
    When using auto steer in a restricted area, it seems like auto steer remains functional i manually increase speed with my foot over the allowed speed. Is this normal?
     
  14. ptsagcy

    ptsagcy Member

    Joined:
    Nov 4, 2013
    Messages:
    446
    Location:
    NJ
    It will only do that on secondary roads. It does not do it on highways and interstates. It will maintain whatever speed you have set regardless of the speed limit on highways and interstates.
     
  15. brucet999

    brucet999 Active Member

    Joined:
    Mar 12, 2015
    Messages:
    1,316
    Location:
    Huntington Beach, CA
    Lots of highways are two lanes or 4 lanes without medians and controlled access; sometimes even with stop signals. (CA highway 41, 49, 88, 89, for example) AP applies speed limitations for such roads.
     
  16. brucet999

    brucet999 Active Member

    Joined:
    Mar 12, 2015
    Messages:
    1,316
    Location:
    Huntington Beach, CA
    Speed control is by TACC and it can be overruled by your foot on the accelerator without shutting off, unlike when you apply the brakes. Auto steer shuts off when you take control of the steering wheel or (I think) when you exceed the 90mph maximum.
     
  17. CHG-ON

    CHG-ON Still in love after all these miles

    Joined:
    Jun 24, 2014
    Messages:
    2,766
    Location:
    Santa Cruz Mountains, USA
    Thanks! You are totally right.
     
  18. xkwizit

    xkwizit Member

    Joined:
    Jan 12, 2016
    Messages:
    618
    Location:
    Folsom, CA, United States
    Correct..TACC will not go over 90mph though you can press the accelerator on your own and go faster.
     
  19. SSD420

    SSD420 Member

    Joined:
    Mar 29, 2016
    Messages:
    854
    Location:
    ON, Canada
    Does anyone else use autopilot 90%+ of the time? I do for highways and 30% on city roads.

    Any idea what would happen if let's say a deer jumped in front of the car?
     
  20. Saghost

    Saghost Active Member

    Joined:
    Oct 9, 2013
    Messages:
    3,038
    Location:
    Delaware
    I think - I hope - that automatic emergency braking would kick in. Similar radar is capable of detecting pedestrians pedestrians at 100m, who presumably have about the same radar cross section as a deer.

    I haven't read of a test case yet, and I have no particular desire to experiment, but if it doesn't react this way now it probably will at some point in the future.
     

Share This Page