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Auto parking -- steering while not moving is not ideal

Discussion in 'Model S' started by Lex, Jan 14, 2016.

  1. Lex

    Lex Member

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    I got to test the perpendicular (ie. typical parking lot) auto parking a couple of times this week and I'm just not going to use it unless it is tweaked. Not because it does a bad job parking, it does OK there but like with the parallel parking there is far too much steering while not moving.

    The last time I tried it, we drove back out, and pulled back in, which is fine, but there was aggressive steering all around, almost all of it occurring while completely stopped. It had me clenched every time. If this had been a fine American product from my past I'd be terrified at the stress to the steering linkage. No fear with that here of course with the best car in the world but there are tender and expensive treads that take all that magic to the pavement. Did I say the tires are expensive already ? I'm not a material scientist but I am 100% sure that this is ridiculously stressful to the tires, especially considering the weight of the Model S.

    I'm hoping to see the kind of coding and logic prowess that went into the orig. "rubber band" power gauge here... not an insurmountable challenge to make car move a bit and then steer.

    It's not like I'm suggesting we should see driver profile changes trigger all the adjustments at once or anything :wink: For the record I imagine we may not have that due to added stress to the 12V system, but that shouldn't mean anything for this, even if the steering is powered off the 12V. I'd even bet less power is needed to turn the wheel when the car is moving.
     
  2. David29

    David29 Member

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    I share your concern, although I have seen dissenting opinions elsewhere.
     
  3. sorka

    sorka Active Member

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    I guarantee that flying around a corner puts 10 times as much stress on the linkage as it does sitting still. If you didn't have power steering, the amount of force you'd need to exert on the steering wheel to hold a 5000 lb car flying around a tight corner would be more than you could handle.

    Also, the stress exerted on the steering linkage pretty much directly on the steering rack without any stress on the steering shaft or steering wheel:

    model-s-front-subframe.jpg
     
  4. roblab

    roblab Active Member

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    My entire back yard is my entrance to my garage. 6000 sq ft. When I resurface it, I am very aware how nearly everybody turns tires without moving, making marks in the resurface paint. Now, I was taught not to do that, but in my 50+ years of driving, I have seen that people are not trainable, mostly. It is obvious that the car and tire makers have figured this out and built the cars to be able to do it.

    I would imagine that bringing a car down from 80 mph off the freeway to a stop at the end of the off ramp burns up more tire. Even more fun, how about zero to sixty in less than 5 seconds? Although it might seem that turning without moving would rip up the tire, I would like to see some proof. I doubt it is worth the time to look it up, and it looks like you agree.
     
  5. AWDtsla

    AWDtsla Active Member

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    When will this myth die. Sounds like a job for MythBusters.
     
  6. Larry93428

    Larry93428 Member

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    15 years old, 1955 working in a gas station, some guy complained about the new "power steering" and that women drivers would grind the tires off turning while not moving.
    I guess that's still a problem.
    Give Tesla time. These features will be refined.
    ~Larry
     
  7. Lex

    Lex Member

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    There's some proof right there. Physical evidence of how additionally stressful turning while not moving is. It literally scrubbed the paint from your driveway.

    I am not suggesting tires would suffer the sort of wear that slowing down or steering etc. does, but am thinking more structural damage that would go on to cause wear -- or worse -- later on.

    And if it is enough stress to peel paint, then it is obviously more stressful, ie. consuming more energy something many if not most TMC members are interested in avoiding, especially if it spikes the 12V system which I imagine it probably does.

    And again, I have no doubt that the MS can take it.

    I am surprised that there is any argument here.

    Amen.
     
  8. eye.surgeon

    eye.surgeon Member

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    I would agree that Tesla needs to add a slow creep with the wheel turning. I don't know if it's myth or fact but I was always taught never to crank the wheel while sitting still and it makes my teeth clench when people do it.
     
  9. AWDtsla

    AWDtsla Active Member

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    Who the hell has paint on their driveway? Even on concrete you are supposed to use epoxy since paint will not adhere to it strong enough to handle vehicle traffic.

    Are you guys worried about rays from wifi giving you cancer too? Maybe it's wind turbines giving you headaches. Maybe it's vaccines giving you autism.


    give me a break....

    - - - Updated - - -

    Stop thinking about what you were taught and think about what is true.
     
  10. CHG-ON

    CHG-ON Still in love after all these miles

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    Agreed. Pisses me off when people turn their stopped tires on my newly sealed driveway and tear up the hours of work I have put into making it pristine. It's clear to me that turning tires while not moving eats up some tread. Probably not much. But more than while moving. I don't do it.
     
  11. theslimshadyist

    theslimshadyist NashVegas!

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    Agreed, I don't think I'd be inclined to use this feature but I certainly would opt for assisted parallel parking.
     
  12. Canuck

    Canuck Active Member

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  13. ohmman

    ohmman Maximum Plaid Member

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    The term for this (turning the steering system without moving) appears to be called "dry steering" or "dry turning." I was right there with AWDtsla because it seems to me that turning is turning, whether in motion or at a standstill. However, I do remember driving vehicles without power steering and I always allowed the vehicle to roll because it was so much easier to turn the wheel, so I started to think maybe the arguments were correct.

    I've researched for the last half hour, and the reliable information I've found is surprisingly slim. Plenty of anecdote, of course! However, it does appear (somewhat inconclusively) that there is additional wear from dry steering/dry turning. It makes some sense - the intuition is that the friction from the sticky tire doesn't get released when you're standing still. If you roll a bit, that friction gets released and you "start over" on the tension in the system. Each time you add tension, a bit of a roll will release it, etc. So I think there is some support for this notion.

    All of that said, it also appears that modern vehicles are designed to easily deal with this stress. The wear on the tires is lost in the noise compared to everything else you do in the vehicle, as mentioned upthread. So yeah, they probably could keep the car from doing dry steering, but the real benefit would just be keeping some owners from cringing.
     
  14. MikeL

    MikeL some guy

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    #14 MikeL, Jan 15, 2016
    Last edited: Jan 15, 2016
    Guys, guys you're barking up the wrong tree. It's not tire rubber (or your nice driveway surface), turning while not rolling puts lots of extra stress on the front end components: tie rods, ball joints (does a Tesla even have "ball joints"?) I only know this from wearing out so many in my trucks, with heavy loads.

    even though a tesla has no heavy engine weighing down the front end, it's heavy overall so ...?
     
  15. DougH

    DougH Active Member

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    I have used this feature and love it, helps with curb rash as well.
     

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