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Polite, safe and effective drafting

Discussion in 'Model S: Driving Dynamics' started by Discoducky, Jul 17, 2013.

  1. Discoducky

    Discoducky Active Member

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    On our drive back from TESLIVE we used some technics for drafting that I've used in cycling races and I'm wanting to get a feel for what folks think about drafting in general.

    For instance: Drafting is more of an art than science as you can hop on and hop off without the 'mark' (car in front) even knowing you are there or just not minding you are there since you are being polite and safe.

    And don't get me wrong, this is more of a discussion on understanding the car's acceleration difference than anything else.
     
  2. brianman

    brianman Burrito Founder

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    I think you got Francis hooked.
     
  3. dhrivnak

    dhrivnak Active Member

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    After being pulled over by a cop to get a warning $15 to which they added $75 court fee and now seeing a jump in insurance due to a "citation " i do not think i will be drafting again. The traffic was light and we NEVER came close to an accident. And with the other drivers being 18 wheelers and i in my Roadster i do not see how i scared them.
     
  4. GSP

    GSP Member

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    I would just maintain a safe two second following distance. Less of a draft, but no possibility of a ticket. It would be nice to have ACC to do this automatically.

    GSP
     
  5. ElSupreme

    ElSupreme Model S 03182

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    Did you guys form a paceline??? :love:
     
  6. wycolo

    wycolo Active Member

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    Appears to be an ongoing campaign against 'messing with semi's' among other road-safety foci. Might be better to steer clear of the big boys lest some road nanny sees extra points in his near career.
    --
     
  7. Zextraterrestrial

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    I wanted to make a sign that says ' May I draft behind your vehicle?" or something
    some people get pissed off if you try and follow between 1 and 2 seconds behind.
     
  8. ElSupreme

    ElSupreme Model S 03182

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    In Atlanta we call that 'leaving a gap'.
     
  9. pete8314

    pete8314 Vendor

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    In Dallas they call that 'defensive driving'. Seriously, it seems like every old clunker round these parts is constantly drafting behind me!
     
  10. AnOutsider

    AnOutsider S532 # XS27

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    haha, I was thinking similar... Who drives more than that?
     
  11. Zextraterrestrial

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    but when there is no traffic on the road and you try and draft someone it is a little different. I know I'd get a little disturbed if I was the only car on the road and someone was trying to tailgate me.
     
  12. AnOutsider

    AnOutsider S532 # XS27

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    True enough there. I'd probably signal for the person doing it to go around.
     
  13. Kaivball

    Kaivball Member

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    This.

    Drafting violates current DMV regulations.

    You are supposed to stay 2 seconds back.

    To effectively draft you have to be within 20 feet, depending on speed and profile of leading car.

    I don't recommend it.
     
  14. Discoducky

    Discoducky Active Member

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    #14 Discoducky, Jul 18, 2013
    Last edited: Jul 18, 2013
    Once you get a taste for how to do it (efficiency gained and NOT getting noticed doing it, it is hard to stop). For everyone following this thread I will say this: There are lots of ways to draft and I would argue only a few ways to do it without getting noticed. For instance: while there is light traffic you should do everything to a lesser extent like 'don't follow closely' and stay at the end of the 'draft shadow' for a much shorter time.

    And this is why I believe some would be interested so things like that are less likely to happen.

    This is usually a good rule of thumb but in heavy traffic (I'm looking at you California!) might be equally as dangerous. A different way to look at the dynamics of drafting in heavy traffic would be to just 'do what everyone else is doing' but do it a little bit safer. In heavy traffic most cars tend to follow too closely and this actually 'decreases' the efficiency of drafting since you are in the very turbulent eddies and not being pulled along by the 'apparent wind' created in the 'draft wake' (great, now I'm using sailing terms...)

    Paceline would have been cool and does work really well for bikes and even NASCAR, but unless the traffic is super light it is not advised. I'd be happy to do this at Laguna Seca ReFuel 2014 and test some hypothesis with folks though if anyone is interested. I believe we could get 400 miles out of a Model S at much higher speeds if we could paceline or, in the interest of time, try for most efficient lap at speed. My guess is that with proper drafting a car could see as high as 20% power savings even during a high speed lap (but let's save that for another thread)

    I'll say this simply: Drafting semi's can be done even at 200' or greater (well back from being able to see the semi's side view mirrors) as you are still well inside the 'draft shadow'. Even at the tail end of the shadow you can achieve 5 to 10% gains. And also note that this applies mainly flat roads at constant highway speed.

    I wouldn't advocate drawing attention to your vehicle as I would advocate that being more discrete and subtle ends up being safer overall

    The gap is the key where whomever you are drafting believes you are 'not following' and is not bothered at all while you are there and the next time they think about it you are already gone.

    Common mistake folks make is to hang on too long and too close, following every move. Truth is, good drafting is knowing when to pick up faster leads and when stay 'tucked in'

    Light traffic drafters tend to stand out and everything you do needs to be more subtle.
     
  15. MichaelS

    MichaelS Member

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    Î have found that you can obtain a pretty good draft in the lane next to a big rig if you position yourself right behind the "bow wave" off the nose of the truck.

    If you watch your power when in cruise control as you slowly pass a truck you can see the drop in power and then a huge spike in power as you move past the front of the truck. The draft is not as good as behind behind the truck.
     
  16. Alpha

    Alpha Member

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    If we could only put a big tube around the highway and suck out all the atmosphere... oh wait, isn't that the hyperloop :smile:
     
  17. cybrown

    cybrown Member

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    Discoducky, can you elaborate on this "correct", "ninja-like" way to do drafting? All I know about drafting is "drive close to the car in front of you", which I've always thought was dangerous. How do you do it correctly/safely?
     
  18. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    Reduced air pressure actually exists for quite a ways behind the vehicle in front. Even at 250 feet there is significant reduction behind a truck. Even better is if you are in a line of vehicles because multiple vehicles create a kind of wind tunnel.
     
  19. Johan

    Johan Took a TSLA bear test. Came back negative.

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    How about in front of a big truck? In cycling there can be 10-20% efficiency gains of you're in 1st of the pack as opposed to riding alone. Of course in cycling you are "on the wheel" or rather the persons behind you are on your wheel.
     
  20. AnOutsider

    AnOutsider S532 # XS27

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    If you're doing it for training or exercise, isn't that cheating?
     

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