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Coasting vs. Gliding

Discussion in 'Gen 3 Prius Main Forum' started by cary1952, Jul 25, 2013.

  1. cary1952

    cary1952 Member

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    Please define the difference. I think coasting is foot off the accelerator, and gliding is light pressure resulting in no arrows showing. Is that correct? And which is more efficient and when should you use each strategy? Thanks.
     
    #1 cary1952, Jul 25, 2013
  2. CaliforniaBear

    CaliforniaBear Clearwater Blue Metallic

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    When you take your foot off the accelerator you will generally actually be applying a small amount of regenerative braking. I would consider coasting to be moving in Neutral. There's not much reason for that in a standard Prius. However, in the Plug-in Prius some folks use that to keep the ICE from starting if they are going downhill and the battery is fully charged.
     
    #2 CaliforniaBear, Jul 25, 2013
  3. cary1952

    cary1952 Member

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    So what is it called when no arrow are showing?
     
    #3 cary1952, Jul 25, 2013
  4. CaliforniaBear

    CaliforniaBear Clearwater Blue Metallic

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    That's gliding. It takes some practice the work the accelerator to keep gliding. Having the ECO function on helps because the car is somewhat less sensitive to accelerator position. If the PWR function were on exactly the opposite occurs, the car is very sensitive to accelerator position for quick power response.
     
    #4 CaliforniaBear, Jul 25, 2013
  5. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
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    Here are my personal definitions. Please note: my definitions are not official, final, or indicative of others' opinions.

    Coast: no pressure on either accelerator or brake. In this mode, there is regenerative braking taking place naturally.
    Glide: No arrows. This requires the foot on the accelerator in order to avoid engaging Coast or acceleration.
    Regenerative Braking (capital R&B): Light pressure on brake to manually engage a higher level of regen than coasting alone. This works only at speeds above 7mph which is when friction braking engages.

    Using my definitions, I:
    - Coast to a stoplight if I anticipate it will change to green before I get there.
    - Glide if I want to conserve fuel and not lose speed.
    - Regen to a stopping situation such as stop light, construction, or bottleneck.
     
    #5 TonyPSchaefer, Jul 25, 2013
    Michael M. Maslowski likes this.
  6. The Electric Me

    The Electric Me Go Speed Go!

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    I actually only have a few months of standard Prius driving, repeatedly and routinely.

    But my observation is that The Prius seems intelligently designed to return great gas mileage using pulse and glide. HSD seems to make the most out of momentum, and so I find myself often accelerating relatively aggressively but then once I reach the speed and momentum I need or want, trying to work in concert with the whole HSD system to return the best gas mileage.

    At that point to be honest I don't pay too much attention to whether I am actually technically "gliding" or "coasting". I would "assume" that gliding is the slightly more efficient state to be in, as max MPG's are being returned without the system working at anything. But I also let the system work in it's own best interest. If I'm coasting but the battery is also getting some regen then that can be a benefit when I reach an urban area where I'll be driving 30 miles per hour or less.

    I know from years within Prius Chat that I am far from being an educated and dedicated hypermiler. Frankly I've been impressed with how "forgiving" and amazing the HSD in the Prius operates, even when driven without any thought what so ever.
     
    #6 The Electric Me, Jul 25, 2013
  7. CaliforniaBear

    CaliforniaBear Clearwater Blue Metallic

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    Those definitions are certainly reasonable. However, your coast is a form of Regen with less regen and less breaking. What would you call Neutral (to be used carefully and only at low speeds)?
     
    #7 CaliforniaBear, Jul 25, 2013
  8. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
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    Neutral is "Neutral"

    And yes, there is regeneration with Coasting. No doubt.
    There are two stages to regen: coasting regen and braking regen. They both use the same principal to pull rotation from the wheels and generate electricity. The difference being that the amount of regen is increased with Regenerative Braking.

    Hobbit has a really cool display in which he can switch between Glide, Coast and Regen. He has you turning a crank, acting as the wheels. At Glide, you turn and turn freely. At Coast, you struggle. At Regen, you have a better chance ripping your arm off than turning the crank.
     
    #8 TonyPSchaefer, Jul 25, 2013
    Michael M. Maslowski likes this.
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