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Introduction to Dynamic Cruise Control

Discussion in 'Fred's House of Pancakes' started by bwilson4web, Mar 23, 2018.

  1. bwilson4web

    bwilson4web BMW i3 and Model 3

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    In another forum someone equated drafting with dynamic cruise control. Referencing MythBusters, they claimed drafting doesn't work. It was easy enough to cite the actual report showing drafting fuel savings is a function of distance. But manual drafting is nuts and that was the message from MythBusters who did not have access to dynamic cruise control in 2007. Dynamic cruise control is NOT drafting so I took my cell phone camera to the highway to get some video.

    Driving a BMW i3-REx with dynamic cruise control set to the minimum distance, I scarfed these images:
    [​IMG]
    This is as close as dynamic cruise control wants to be at 65-70 mph. The leading pickup is along side the truck and the trailing pickup is about 2/3d closer. The truck is my pacing vehicle.

    [​IMG]
    Here are the next pair who could easily fit. That is drafting and nuts. But they are not following me as much as wanting to get past the truck. Meanwhile I'm sitting in a comfy chair just staying in my lane, feet flat on the floor.

    Yes, dynamic cruise control is close enough to feel some burble, the transition to drafting. Use it in a misty rain, you can see your not fighting the aerodrag alone. But we're not talking great fuel saving as much as letting the pacing truck do the heavy lifting and smooth the normal speed transitions on the road.

    Learning to to use dynamic cruise control is not easy. It means breaking a lifetime habit of controlling the speed manually or even using a fixed-speed cruise control. With practice and experience it become second nature. Yet I still get a little angst when the pacing vehicle is coming to a stop.

    Bob Wilson
     
    #1 bwilson4web, Mar 23, 2018
    Last edited: Mar 23, 2018
  2. tochatihu

    tochatihu Senior Member

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    I understand it is generally the case that lane stripes are 3 meters long with 9 meter spacing. If reliable, then all such photos have built-in scale bars.
     
    pilotgrrl likes this.