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Anyone shift into "Park" when going uphill at a stoplight?

Discussion in 'Model S: Driving Dynamics' started by Hometheatremaven, Mar 12, 2014.

  1. Hometheatremaven

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    When I owned an ICE, I would always turn off the engine when I knew I would be stopped at a light for > 1 minute.
    With my MS, I don't have to worry about wasting energy at a light.

    But when I'm headed uphill at a long light, I still shift into "Park" so I don't have to hold my foot on the brake.
    Does this use more or less energy (the car's, not mine) than keeping my foot on the brake?
     
  2. Doug_G

    Doug_G Lead Moderator

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    No difference. Shifting to park activates an extra pair of calipers on the rear wheels. Two small electric motors run for a few seconds to engage the calipers, then power down. At that point it takes zero energy to hold the car in place. It has to work - this is how the car stays put while powered down!
     
  3. JohnQ

    JohnQ Active Member

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    The extra second it takes to engage the brake pedal and shift into drive would trigger honks and extended middle fingers here :)
     
  4. neroden

    neroden Happy Model S Owner

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    I only do it at really long stoplights. (You know the ones, with a dozen different cycle elements.) But yeah, Park saves wear and tear on my leg.
     
  5. Discoducky

    Discoducky Active Member

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    I use my left foot for the brake only in this situation, since there is no hill hold, so that the car does not roll back. I drive hills every day so I get lots of practice.
     
  6. mknox

    mknox Well-Known Member

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    ..but adds extra wear and tear on the power door handles. Sometimes I wish I could just park and have the handles stay put. They don't need to extend when, for example, I'm just getting OUT of the car.
     
  7. Brass Guy

    Brass Guy Member

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    Just use the parking brake on the touch screen. That's what I do. It's pretty much the same as "park" except no door handle extension and the dome lights stay off.

    Uhm - not if you're leaving the car though...
     
  8. mknox

    mknox Well-Known Member

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    That's interesting... I'll try that!

    Why not if you're getting out, though? Putting the car in Park and applying the Parking Brake are one and the same with the Model S. In both cases, it is simply applying a power operated brake on the rear wheels.
     
  9. Zextraterrestrial

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    interesting idea. (Mknox - if you get out the car won't turn off/lock- I think that one way to keep it on)

    I started using my left foot at stoplights. then when you mash the throttle it looks like no lag at all between brake lights going off and car zooming away.

    hill hold will be on next version update but I think that it is only good for a short period like going from brake to go pedal.
     
  10. Brass Guy

    Brass Guy Member

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    Yes, if you apply parking brake instead of "park", the car will remain on when you exit. I would guess that means someone could sit and drive away without the fob, since the car is not off. Does "walk away lock" still work in this case?
    Also I don't think the car will go to sleep.

    Parking brake works fine for long stop lights. I used to use "park", but needed to find a way that didn't extend the handles. And at night when all the interior lights turned on - I didn't want to be on display!
    I've also started using the 2-pedal method of hill starts. It's better than rocking back towards the car behind. Countering that reverse momentum with all the sand and salt still on the roads invites undesired wheel slip. And drivers of automatics get quite close sometimes.
     
  11. Gizmotoy

    Gizmotoy Active Member

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    I'd been driving a manual exclusively for quite awhile prior to my S, so I'm used to the quick transition from brake to gas. As Zex. said, my rep at the SC told me hill hold is definitely in the next major release (he'd personally been in a test car with it), so it won't be a problem for you for long.
     
  12. Hometheatremaven

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    As the OP of this thread, I can say that I've learned the answer to my original question. It does take more energy to put it into "Park" because doing so expends extra energy extending the door handles. I hadn't even thought of this unintended consequence. Don't really understand why the handles need to extend when I'm getting out of the car.

    As I also grew up with a stick shift, I have no problem using the brake uphill, other than getting bored holding my foot on the brake.
    But now I'm wondering if the hill holder feature will consume power, and if so, how much. I guess I'll use it but wonder if it's defeatable.
     
  13. Zextraterrestrial

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    Hill hold is said to use the e-brake for a second or so and be defeatable like the creep mode is
     
  14. Brass Guy

    Brass Guy Member

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    I would appreciate it being defeatable. I also have mostly driven manuals, but will give the hill hold a chance. The two-feet method just smooths out some of the steeper starts.
    I'm pretty sure that either ”park” or parking brake (neutral) would save energy though, because it looks like if you take the car out of gear the energy bar drops just noticeably after 2 seconds. Door handles and interior lights aren't enough to make the meter move.
     
  15. deonb

    deonb Active Member

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    I just hold the car in place with the accelerator.

    Tesla Service assured me it doesn't cause undue stress on the drive system.

    Takes practice, but after a while you can hold it perfectly still. I'll switch to break if there are pedestrians walking in front of the car though.
     
  16. Brass Guy

    Brass Guy Member

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    I'm sure the drivetrain can handle that small amount of force, but as far as energy efficiency goes that wastes the most!
     
  17. mknox

    mknox Well-Known Member

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    I honestly can't see the need for hill hold. It is useful on manual cars because humans don't have three feet, but with the Model S you just hold the brake with your left foot and the accelerator with your right. I do this all the time. Further, I don't need the extra wear-and-tear with the e-brake going on and off all the time.
     
  18. Doug_G

    Doug_G Lead Moderator

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    Hill hold could be done with the drive train instead of the E-brake. A little forward power to balance gravity.
     
  19. andydoty

    andydoty Member

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    Hill hold would be a fantastic feature! However, as a point of clarification. I believe most ICE vehicles do not apply brakes per se, they set a parking pin the transmission. I could see, and have, switched into neutral at a light to release some of the stress on the engine. I would think the Tesla would be happy with just applying the break. The break compressor can't use that much juice.
     
  20. woof

    woof Model S #P683 Blue 85 kWh

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    Hill Hold on the ActiveE uses the friction brakes. Once the brakes are manually applied (via the foot pedal), on an upward slope they will stay applied even when the brake pedal is released. They continue to be applied until the accelerator pedal is pressed, or two seconds elapse. After two seconds the brakes are released and the car may drift backwards. The idea is to prevent the car from driving backwards on a hill while the driver is moving his foot from brake to accelerator.
     

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