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when MPG is dropping, what should I do?

Discussion in 'Gen 2 Prius Fuel Economy' started by myue, Nov 11, 2013.

  1. myue

    myue Junior Member

    Joined:
    Dec 28, 2011
    10
    1
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    Location:
    California
    Vehicle:
    2008 Prius
    Model:
    II
    the MPG is dropping on my 2008 Prius, dropped about 10%, so 5mpg less.

    I recently put a new set of Tires On, bought from Costco, Michelin.

    The car is about 100k miles.

    I noticed sometimes, when not press gas paddle, the MPG don't jump to 99Mpg as it used to and sometime on Freeway when maintain the same speed, before the MPG would be easily over 50 even at 70-80 easily, now it goes to 40.

    is that indicate the battery is old?

    BTW, for the 12v battery, I had Toyota replaced it for me in 2010 spring when the car is at 25k, (since back then, one day the car won't start) if I replace it now, will it improve MPG?

    Thanks.
     
    #1 myue, Nov 11, 2013
  2. vskid3

    vskid3 Active Member

    Joined:
    Jun 23, 2013
    773
    228
    0
    Location:
    Texas
    Vehicle:
    2005 Prius
    What model are the tires? Michelin makes tires that range from great to terrible for mileage. What tire pressure is in them?
    The 12v battery is probable fine unless you've run it down before. You can test it and see, but I think the tires are probably your problem.
     
    #2 vskid3, Nov 11, 2013
  3. dorunron

    dorunron Senior Member

    Joined:
    Jul 17, 2011
    3,318
    1,104
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    Location:
    Houston, TX
    Vehicle:
    2013 Prius
    Model:
    Three
    #3 dorunron, Nov 11, 2013
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