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Emergency Brake Affecting Mileage

Discussion in 'Gen 2 Prius Fuel Economy' started by moshe1436, Sep 8, 2007.

  1. moshe1436

    moshe1436 Bought used.

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    Hi -- I haven't seen this b-4 so excuse me if it's already been covered but I thought it would be of interest.
    Last week I took a 525mi rd trip from Lake George, NY to Hawley, PA (Pocono mountains). On the 1st leg I averaged +/- 57mpg even through the Pocons Mountains in PA (not bad). On the way home the best I got was 50.6mpg. Then after driving around town here I realized something was wrong -- I was not "coasting" down hills as b-4 and it seemed like the vehicle had to work harder to "get going", etc. Then I "reset" the emergency brake, which I had used while in PA, thinking maybe it was partially on, even thought the warning light was not lit. That did the trick and now I'm back to the same performance as b-4 using the emergency brake in PA and my mileage is creepng back up! So my advice is make sure you completely release the emergency brake after using it, because it's obvious that it was dragging my mileage and performance down. Apparently the warning light doesn't stay on if the brake is on a little. Anyone else had this happen???

    Moshe
     
    #1 moshe1436, Sep 8, 2007
  2. efusco

    efusco Moderator Emeritus
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    Always good to remind folks of that, esp. when there's been an unexpected drop in FE like you experienced. It's one of the things I tell folks to check in those conditions but it hasn't been brought up for a few months here.
     
    #2 efusco, Sep 8, 2007
  3. tochatihu

    tochatihu Senior Member

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    Beginning with a cold car, drive a mile or 2. Then stop and apply a wet fingertip to the rear brake drums. If you get a sizzle, your shoes are dragging.

    Also, cycling the pedal once in a while can help keep the mechanicals sliding nicely. Esp. recommended for winter road salt areas.
     
    #3 tochatihu, Sep 8, 2007
  4. moshe1436

    moshe1436 Bought used.

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    <div class='quotetop'>QUOTE(tochatihu @ Sep 8 2007, 10:34 PM) [snapback]509330[/snapback]</div>
    Good suggestion -- I knew this was important for other cars I've owned -- guess it still applies here. Thanks,
     
    #4 moshe1436, Sep 9, 2007
  5. Bill Lumbergh

    Bill Lumbergh USAF Aircraft Maintainer

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    Hondas I had worked with previously were equipped with an ABS system sensitive enough to detect the emergency brake being on. The ABS light would illuminate not long after the drive began, since it noticed one or more rear wheels were turning slower than the fronts.

    I would think the Prius would trip an ABS light for the same reason.
     
    #5 Bill Lumbergh, Sep 17, 2007
  6. qbee42

    qbee42 My other car is a boat

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    <div class='quotetop'>QUOTE(Boxster...WRX...Prius? @ Sep 17 2007, 06:00 PM) [snapback]513921[/snapback]</div>
    That would only be true if the rear wheels were slipping to some degree. If the brakes are creating a drag on the rear wheels, but not enough to make them slip or skid, then the rotational speed is the same.

    Tom
     
    #6 qbee42, Sep 18, 2007
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