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Best Fuel Economy Speed (Km/Hr)

Discussion in 'Gen 3 Prius Fuel Economy' started by Hong Kong Prius, Nov 3, 2016.

  1. Hong Kong Prius

    Hong Kong Prius New Member

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    I am a newbabie owning a 2011 Prius and trying to do the best fuel economy.

    When I am driving in a highway at around 80 km/hr or above and try the "glide" technique in order to run the car with pure electricity, the speed would keep dropping very fast and sometime the gasoline will bring in operation.

    Is it the way it is or if there is any tips for getting best mileage?

    Thank you!


    Posted via the PriusChat mobile app.
     
    #1 Hong Kong Prius, Nov 3, 2016
  2. dorunron

    dorunron Senior Member

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    100 km/h is a good speed for economical use, use cruise control on flats and slight inclines.

    Prius is NOT a electric car, but rather a hybrid. Trying to drive it only on electric will not yield best economy.

    If you want electric car, buy a Tesla.
     
    #2 dorunron, Nov 3, 2016
    Last edited: Nov 3, 2016
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  3. drysider

    drysider Active Member

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    You may have different firmware, but my Gen3 won't go into an electric only glide at 80km/h. The fastest is about 70km/h.
     
    #3 drysider, Nov 3, 2016
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  4. Tideland Prius

    Tideland Prius Moderator of the North
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    At 80km/h, it's best not to use the battery. Instead, go into "Super Highway Mode" or "Heretical Mode". This is when you have the gasoline engine directly powering the wheels. In the Energy Monitor, you'll see two versions. Either an arrow from the engine directly to the wheels (and no other arrows) or you'll see the arrows flicker between engine-->motor-->battery and engine-->motor-->wheel.

    Also, in the instant fuel economy gauge next to the speedo, you'll see the fuel economy pegged at 2.5L/100km-3.0L/100km or 35- 40km/L (give or take. It may flicker up and down). You'll lose a little bit of speed but very slowly and if you need to speed back up, just "pulse" back to your desired speed and then go back into that mode.


    Here's some reading material:

    New Prius - "Super Highway Mode" Technique (SHM). | CleanMPG


    Here's what I can get on an undulating 80km/h highway. This is a round-trip distance total (but the 5 min consumption is just for the return trip). 3.2L/100km = 31km/L

    [​IMG]
     
    #4 Tideland Prius, Nov 4, 2016
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  5. drysider

    drysider Active Member

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    Like Tideland said. If you have a ScanGauge you can see the instantaneous mileage, which really helps you understand how the mpg's change. If you want to maximize mileage, be prepared to drive in the right hand lane a lot.
     
    #5 drysider, Nov 4, 2016
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  6. fuzzy1

    fuzzy1 Senior Member

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    Several indications from past threads indicate that the very best fuel economy speed is at approximately 15 mph (24 km/Hr). Or somewher in the range of 10-20 mph (16-32 Km/Hr).

    But that speed range is simply too slow to be practical for most of us. Any higher speeds will consume additional fuel, but because our time also has value, that extra fuel cost is worth it.
     
    #6 fuzzy1, Nov 4, 2016
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