getting 21mpg

Discussion in 'Gen 2 Prius Fuel Economy' started by misterdean, Jan 10, 2017.

  1. DonDNH

    DonDNH Senior Member

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    1. Have you checked the oil level; overfilling the oil can cause poor MPG.
    2. Are the brakes dragging? Emergency brake not disengaged fully?
    3. Check (or have checked) wheel bearings.
    4. Tire inflated to 35 PSI or higher? What type of tires are on the car?

    Even if the hybrid system is completely inoperable, the mileage just from the ICE shouldn't be that bad.
     
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  2. Moving Right Along

    Moving Right Along Senior Member

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    If the emergency brake was left on when he got the car up to 90, it's shredded now! :LOL:
     
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  3. misterdean

    misterdean Member

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    i have been driving it cold. no warm up at all. just start and go. gonna let it warm up from now on. will also take a picture of both screens for you guys after i drive it more. the dealer just sent me the carfax. it's been serviced regularly by toyota up to 85K. it passed emission tests 3k miles ago. dealer service record shows 12v battery condition and state of health as good 3 weeks ago. i have not checked the oil or tire pressure yet. dealer said they do it as part of maintenance for all their cars. i see the tires marked as showing wear. somebody here has asked me what tires twice. will find out. also heard in another thread about these using special tires and people don't know and just throw regular tires on them which leads to poor efficiency. is this information correct?

    [​IMG]
     
    #23 misterdean, Jan 10, 2017
    Last edited: Jan 10, 2017
  4. wjtracy

    wjtracy Senior Member

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    I am under the impression if you reboot the car system (by disconnecting 12v power and reconnecting) the car takes a little while to readjust the software. But I am not expecting 21 MPG. Make sure you hit the reset button on the video screen to make sure you are not carrying over old data averages from the past. Each fill-up we hit that reset to make sure the MPG we are seeing is for the current tank.
     
  5. bisco

    bisco cookie crumbler

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    the only true measurement of mpg's is at the pump. and even then, it takes a few fill ups, averaged out to get a decent reading. especially gen 2 w/bladder tank. why not give it some time before panicking, and spending money chasing ghosts?
     
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  6. misterdean

    misterdean Member

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    will start keeping track at the pump. what is the capacity of the tank?
     
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  7. jerrymildred

    jerrymildred Senior Member

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    Don't warm it up before driving it. That will make your mileage worse. The whole time it's idling (which isn't very long in warm weather, but might be a while in a northern winter) it's getting zero mpg. If you're going to burn gas, make it do something.

    I'll toss in another recommendation to check the 12v battery. It could be running the engine extra as it try to charge a weak accessory battery. But with such low efficiency and no trouble lights, it seems like it may be an accumulation of several things like low tire pressure, low 12v battery, dirty engine air filter, wrong engine oil. Also, check the cabin air filter That can affect mileage if it's extra dirty.
     
  8. misterdean

    misterdean Member

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    does this car need special oil?
     
  9. bisco

    bisco cookie crumbler

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    no, just regular dino. the weight is on the oil cap or in the o/m.

    i think the gas tank is around 12 gallons, but the gen2 has a rubber bladder inside the tank, so, it doesn't always fill properly.
     
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  10. srellim234

    srellim234 Senior Member

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    Simple idea from my simple mind. Have you reset the mpg on the touch screen? The fact that you say it is always hovering around 21 mpg might be an indicator that it is reflecting poor gas mileage over multiple tanks as achieved by the previous owner.

    When you fill up the tank the miles driven on the current tank resets to zero but the mpg. does not. If you haven't reset it already, fill the gas tank and then reset the mpg reading to zero by touching the reset button in the lower right corner of the display. Then test drive it and see if the mpg actually changes..
     
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  11. misterdean

    misterdean Member

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    interesting. i did reset the data when i got in the car for the test drive. the car currently had and still has a quarter tank of gas. i have not filled it yet.
     
  12. dolj

    dolj Senior Member

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    So I'm confused, you pressed the reset button for the test drive and now the Average MPG displays 21 MPG?
    You don't have to wait for the thank to be empty to fill it.
     
  13. misterdean

    misterdean Member

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    i pressed it when i got in the car and was playing with the menu's. it's been at 21 since the day of purchase.

    i know i don't have to wait until the tank is empty. but i was kinda curious to see how long that quarter tank would last and since i don't know how long the gas has been sitting in there or even what else might have been put in the tank so i wanted to burn through it and fill it with fresh BP.
     
    #33 misterdean, Jan 11, 2017
    Last edited: Jan 11, 2017
  14. dolj

    dolj Senior Member

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    If you pressed it when you got the car, it should have gone to zero.
     
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  15. jerrymildred

    jerrymildred Senior Member

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    Not special, as Bisco already pointed out. Just the right viscosity. Throwing in 10w30 or something like that will negatively impact fuel economy to a degree, but wouldn't account by itself for what you're seeing.
     
  16. DonDNH

    DonDNH Senior Member

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    Does anyone find it odd that checking the engine oil isn't on this checklist?
     
  17. misterdean

    misterdean Member

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    pretty sure i already mentioned oil was changed by the dealer a few weeks ago.
     
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  18. valde3

    valde3 Senior Member

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    But it’s just weird seeing checklist without even a check for oil level.
     
  19. Mendel Leisk

    Mendel Leisk Witness Leader

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    Yeah there's something not adding up here. Hopfully get's figured out.

    Also, it's a fool's mission, assessing mpg trip-by-trip. OP should fill the tank, reset trip meter, or even better (more bullet-proof): note the odometer reading. Drive carefully for a tank, refill, note the distance travelled and gas needed to refill, do the mpg math. And what with the second gen bladder tank, repeat the process a few times.
     
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  20. misterdean

    misterdean Member

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    it did go to zero. i've put 78 miles on the car since. i will be doing the math when i fill it up.
     
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