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Just a newb question of mpg vs miles left before tank fill up

Discussion in 'Gen 3 Prius Fuel Economy' started by PutPutMobile, Sep 30, 2017.

  1. PutPutMobile

    PutPutMobile Senior Member

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    I just want to know if this is normal. I don’t really look on the mpg meter often because I know I save mpg now since I flushed my oil and tranny fluid.

    I read on the miles left before fill up screen. When I fill up gas full tank, it reads 446 miles then it goes down to 0 before filling up again.

    Last night, I was driving home from work (within 11 mile distance). I saw the screen it was 377 miles left, warmed up the car. Then I take off. After driving 4 miles in the freeway, I exit the ramp. I noticed my mileage became 368. Then after getting food to go, I drive off again in the streets and while coasting the miles go down from 368 to 355 that’s from a 6-7 mile distance. Never happened to me before since I got the Prius in March of this year. Checked the voltage on the battery and it’s normal.

    I got home then it says 354, but switch to mpg mode and says 46.8 mpg used 108 miles which better than my old version of 43mpg. I don’t slam on the gas anymore since I’m happy my mpg went up again after maintenance.

    Does anyone have this problem after driving 100 miles on the tank.?? Car miles left before fill up 23 miles fuel consumption from 377 miles left to 354 driving within 11 miles. My Prius is 2010 with almost 60k miles on the meter.

    Thanks in advance of your input.
     
  2. bisco

    bisco cookie crumbler

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    the computers base the dte on current mpg, not average, so it probably fluctuates more than you realize.
     
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  3. PutPutMobile

    PutPutMobile Senior Member

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    Oh ok. Got it. Thanks. I have the idea now.
     
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  4. Mendel Leisk

    Mendel Leisk Senior Member

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    I never look at that, just rely on the fuel gauge.
     
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  5. PutPutMobile

    PutPutMobile Senior Member

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    I look at that also.. I just have a stupid habit looking at the numbers..
     
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  6. Grit

    Grit Senior Member

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    Happens to me also. It fluctates but not that much because driving condition changes constantly. If you drive in the city, miles to empty will be higher than miles to empty driving on the highway. If you continue to drive the under the same speed, weather condition, weight load, elevation, miles left will remain fairly constant, but driving conditions always change because no conditions will never be the same. But if your losing 50 miles or big numbers like that, get the car check.
     
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  7. MelonPrius

    MelonPrius Senior Member

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    If you're just looking for a way to see how many more miles you have left, then here's another way to calculate the info in your head.

    Take your average mpg for the tank and multiply it by 10. That should be near the miles when your warning light (flashing light) comes on. If you're averaging 50 mpg, then you'll get the flashing icon around 500 miles. And then you'll have around 2 gallons left as a cushion. You'll likely be off by around 4-7% because the computer is usually optimistic by that amount.
     
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  8. PutPutMobile

    PutPutMobile Senior Member

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    Thanks.. Yes I drive mostly city where the roads constantly changes. I live in the Orange County area in CA. It's fast pace over here. But I still able to drive fairly constant and I don't care if sometimes people tailgate me... LOL..
     
  9. PutPutMobile

    PutPutMobile Senior Member

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    .
     
    #8 PutPutMobile, Oct 5, 2017
    Last edited: Oct 5, 2017
  10. PutPutMobile

    PutPutMobile Senior Member

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    Ohhh I never thought of that.. I'll try that.. Thanks.. I never go down to where my warning light turns on.. I'm kinda ocd about the oil residue from the bottom of the oil tank due to my previous cars.. I fill up when my car is about 2 pips left. Then I calculate from there..
     
  11. PutPutMobile

    PutPutMobile Senior Member

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    Hmm.. Still bringing this question about fuel economy on the prius.. I'm averaging 44 mpg on my 12 miles to work mixed with highway and streets here in Orange County.. Not that much hills I can think of.. I do my best to do the pulse and glide.. My tires are always at 40 psi..

    Most of the time i'm on ECO but lately I love the response on Normal mode.. Anyway I can possibly go up to 50 mpg?

    Maybe I should clean up my MAF, EGR pipe, intake manifold, and change a new 12v battery??
     
  12. Grit

    Grit Senior Member

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    I get that all the time going down hill in power, 99mpg +
     
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  13. PutPutMobile

    PutPutMobile Senior Member

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    :ROFLMAO::LOL:
     
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