1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Validating mpg readout

Discussion in 'Prime Fuel Economy & EV Range' started by HypersonicPrime, Nov 29, 2017.

  1. HypersonicPrime

    Joined:
    Oct 1, 2017
    74
    59
    3
    Location:
    NC, USA
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    Has anyone validated the mpg readout on the Prius Prime with a full-empty drive? For example, start with a full gas tank, place the car in HV mode (depleted battery or save EV driving for before or after this test), reset a trip meter, drive until nearly empty, fill it up again. Calculate mpg by dividing trip meter miles by gallons filled and compare to trip meter mpg. After 2 such trips, the reading I get on the car seems to be higher than I calculate manually by about 4 mpg. I suppose for this question you could include the EV miles, but I'm doing the calculation leaving it out as to not artificially increase my HV-mode mpg estimation.
     
  2. DavidA

    DavidA Prius owner since July 2009

    Joined:
    Jul 14, 2009
    2,329
    1,812
    18
    Location:
    Chicago western burbs
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    The Prius line has always had the problem of reporting higher than actual MPG on the dash. The last two generations of Prii were between 2 and 2.5 mpg higher than long term manual calculations would reveal. I don't care anymore to figure it out, as I have known the about the error for 8+ years. As long as I keep adding electrons to the battery, and not gas to my tank, I'm happy.
     
    HypersonicPrime likes this.