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Unexpected drop in MPG

Discussion in 'Prius c Fuel Economy' started by kdh48, Sep 3, 2018.

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  1. kdh48

    kdh48 New Member

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    2015 Prius c
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    One
    I've had my car for a little over 2 years and usually average 48-56 mpg, and lately it has been struggling to get up to 30 mpg. I've been consistent with oil changes, tire rotations, keeping the correct PSI in my tires, making sure fluids are good, etc. I've also had no change in trips, driving patterns, A/C usage, or anything. Literally everything has been held pretty constant, just a sudden drop in my mileage. Could it be the 12 V battery? I've put 52000 miles on it since I've had it from only 10 miles, but just don't see why it would suddenly drop?
     
    #1 kdh48, Sep 3, 2018
  2. PriusCamper

    PriusCamper Senior Member

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    Sometimes bad gas can do this, or not correctly having the amount of gas in the tank you thought you had. Once this is beyond just one tank of gas, it's time to start doing some diagnosis.
     
    #2 PriusCamper, Sep 3, 2018
  3. fuzzy1

    fuzzy1 Senior Member

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    #3 fuzzy1, Sep 3, 2018
    ztanos and roadrunner like this.
  4. bisco

    bisco cookie crumbler

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    welcome!
    certainly worth testing the 12v to begin with. have you ever discharged it?

    how are you measuring mpg's, calculated when refilling?
     
    #4 bisco, Sep 3, 2018
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