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Fuel consumption drop

Discussion in 'Gen 2 Prius Main Forum' started by sanlen, Feb 9, 2015.

  1. sanlen

    sanlen Junior Member

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    hello,

    My 07 Prius is now at 105237 miles. I used to get more than 55 mpg on highway. However, just lately I always get below 45 mpg. I am thinking of changing the spark plug now.

    Is it the right thing to do? Please also recommend spark plug which fit well with Prius. Other than spark plug, what else should I focus on?

    Thank
    Salen
     
    #1 sanlen, Feb 9, 2015
  2. bisco

    bisco cookie crumbler

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    use the oem plugs. clean the throttle body, check your tyre pressure and test the 12 volt battery. keep in mind, cold weather, slushy streets and winter gas formulation all work to reduce mpg's.
     
    #2 bisco, Feb 9, 2015
  3. sanlen

    sanlen Junior Member

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    Thank for quick advise. What should I conclude after testing the 12 volt battery?
     
    #3 sanlen, Feb 9, 2015
  4. bisco

    bisco cookie crumbler

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    test it in the morning or after a few hours of being off. if it's less than 12.5 volts, replace it.
     
    #4 bisco, Feb 9, 2015
  5. sorka

    sorka Active Member

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    Changing plugs at 100K miles is a good idea and the recommended change interval.

    However, the most common and most overlooked cause of dropping fuel economy is poor wheel alignment.
     
    #5 sorka, Feb 11, 2015
  6. alekska

    alekska Active Member

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    I would not mind to have a fuel consumption DROP (as in OP's title)

    - Alex
     
    #6 alekska, Feb 11, 2015
    Last edited: Feb 11, 2015
    edthefox5 likes this.
  7. Mendel Leisk

    Mendel Leisk Senior Member

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    Wheel drag might also cause a drop in mpg. Could be misalignment, as mentioned above, brake neglect causing drag for one reason or another, or even low tire pressures.
     
    #7 Mendel Leisk, Feb 11, 2015
  8. sanlen

    sanlen Junior Member

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    Thank for advise.
    Just changed the spark plug and made a 600KM trip. I get 51 MPG now.
     
    #8 sanlen, Feb 16, 2015
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