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How do I calculate MPG?

Discussion in 'Gen 2 Prius Main Forum' started by JanLWatson, Apr 20, 2005.

  1. JanLWatson

    JanLWatson New Member

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    We are now a 2-hybrid family. Purchased a Honda Insight 6 months ago, and now the Prius this past weekend (4/16/05).

    The Insight maintains average MPG for the lifetime of the car (LMPG), Trip A, Trip B, as well as 'segment' of travel.

    I am confused with the Prius's average MPG functionality. Is there only 1 average kept? I read something in the manual that suggested it automatically resets itself after about each 2.5 gallons of gas.

    How do you keep track of MPG? Perhaps the old fashioned way of writing it down gallons added at each fillup as well as odometer reading, and then use a hand caluclator?

    The Prius blows the Insight away! What a car! I drive 9 miles each way for work, and am got 65.7 MPG on trip to work this morning with the Prius (Constant stop/go in heavy traffic).

    It appears to me the primary difference between the two cars is that with the Insight, the electric motor assists the gas engine --- whereas on the Prius, the gas engine assists the electric motor.

    My Insight is CVT as well. I average about 68 MPG highway with the Insight.

    I suspect I will get better mileage with the Prisu in the city, and the Insight on the highway. Time will tell! Only 150 miles on the car so far.

    Any help with the average MPG question would be greatly appreciated. Thanks.
     
    #1 JanLWatson, Apr 20, 2005
  2. KTPhil

    KTPhil Active Member

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    The only way to get LMPG is the old fashioned way.

    The car resets the internal calculated MPG when you add about 3 gallons or more. The odometer is not changed, though, just the internal MPG tracking.

    The Prius is much more spohisticated than just "gas helps the electric." The PSD also manages regeneration, charging, power, and overspeed protection.
     
    #2 KTPhil, Apr 20, 2005
  3. richard schumacher

    richard schumacher shortbus driver

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    Lifetime MPG settles down to an almost unchanging figure.

    Just use the Prius' displayed MPG. It's more accurate than you can do manually, unless you carefullly put in the same amount at each re-fuelling instead of filling it.
     
    #3 richard schumacher, Apr 20, 2005
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