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Gas Tank Mystery Solved?

Discussion in 'Gen 1 Prius Plug-in 2012-2015' started by SimiPrius, Jan 31, 2013.

  1. SimiPrius

    SimiPrius Member

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    We have all wondered why we can only get 7+ gallons of gas in the car when the gauge says we are almost empty. I have a friend who has a PIP and decided to "test" the gauge. He was at about 400 miles when the car said he had about 1 bar left. Shortly thereafter, the last bar began blinking and the dashboard readout said that he had about 8 miles left. Well, he finally ran out of gas at 560 miles - about 160 miles over from where the car was telling him he was almost empty. When he filled up, the car took 10.5 gallons - about what it should. Either Toyota has done a poor job of programming the gauge, or they are just being conservative for those that may push the envelope. I would tend to beleive the latter.
     
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  2. Edsvfr800

    Edsvfr800 Member

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    Reminds me of Kramer test driving the car on Seinfeld.....LoL.
     
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  3. jdcollins5

    jdcollins5 Senior Member

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    It is the latter. In the Gen II you could run out of gas and still use the HV battery to get to gas station. Many people abused the use of the HV battery resulting in premature battery failures in some instances.

    In the Gen III when you run out of gas you can no longer use the HV battery, so they are being conservative to keep you from "dying beside the road".

    There are many threads on here if you want to bother to search.
     
  4. SLOW_RR

    SLOW_RR Member

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    When I picked up my PIP, the last thing the salesman said to me before I drove away was, "Don't run it out of gas!" In fact he said it twice... So I am taking his word and filling up at about 1/4 tank or a little less, especially if I am going to be driving on interstate highways at all... LOL
     
  5. john1701a

    john1701a Prius Guru

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    There is an extensive history (dating back to 2001) detailing how the decision of when to suggest refill was made.

    Search this forum. Then search the internet for the information from the Classic model, prior to discussion here.

    It is a sensible choice when all of the variables at play are known... especially consumer behavior.
     
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  6. retired4999

    retired4999 Prius driver since 2005

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    I fill when I See two bars. No reason to push it! just my peace of mind. :D
     
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  7. jdcollins5

    jdcollins5 Senior Member

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    +1 Agree :)
     
  8. devprius

    devprius /dev/geek

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    My personal experience is that the car is smart enough not to let that happen and will protect the battery at all costs. I ran out of gas at least 4 times in my Gen II. Every single time it happened, the car was smart enough to not let that last battery bar disappear. Power gradually dropped off until I either made it the gas station, or pulled over safely. It never let me completely drain the battery past that safe level. At the time I didn't have a Scan Gauge, so I don't know how low the SOC is allowed to get it before the car says "get some gas dude, we ain't going no where".

    I have a hard time believing that pushing the car like that would result in premature HV battery failure, unless you did something to further push things, like repeatedly trying to restart the car after you have dropped to that last bar and been forced to pull over, but before you've gotten gas.
     
  9. DianneWhitmire

    DianneWhitmire High PRIUStess

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    When the little car icon next to the gas tank says 0, I get gas immediately.
    And, it will only take MAX 8.5 gallons.
    I'm known for pushing the envelope for time/gas fill ups and have admittedly run out of gas in every Prius I have owned at least twice.. and my 2007 even more than that. The worst instance of running out was on 10/10/10 in Malibu... but we shant speak of that again!
    Now, with 23K on my plugin, I have yet to run out of gas or even come close. I'm not willing to risk the car's battery and technology... not this car! It's my favorite Prius yet! :)
     
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  10. devprius

    devprius /dev/geek

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    The most I've put in a tank so far is 9.37 gallons.
     
  11. retired4999

    retired4999 Prius driver since 2005

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    The most I've put in 9.0 gallons gas.
     
  12. Totmacher

    Totmacher Honey Badger don't give a carp

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    I put 10.2 - 10.5 in pretty much every fill....

    The pump will click off at around 7-8 gallons from dead nutz empty. You can manually get 2+ gallons in after that. I look at it as spending 3 more minutes at the pump toping off buys me an aditional 300+ miles or 2 wees of driving... Worth it to me.
     
  13. bisco

    bisco cookie crumbler

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    how many miles past '0 miles to empty' do you typically drive?
     
  14. Totmacher

    Totmacher Honey Badger don't give a carp

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    You can't really answer that question. My daily commute is 15 miles pure electric down hill to work and 10 miles electric up hill 5 miles gas home. So I can go 3-4 days past zero or technically 120 miles. because only 25ish of it is actually past zero. I typically go fill up between 0 and 10 miles of gas engine past the zero. but if I know I'll be electric for a few days I push it.
     
  15. bisco

    bisco cookie crumbler

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    i meant dte which is gas plus whatever ev charge is available. i don't understand how you're emptying the gas tank without going 100 miles or so beyond dte.
     
  16. Chris_SoCal

    Chris_SoCal Junior Member

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    I don't agree. My PIP was filling one night a few weeks ago and I went inside to get some Monster Energy Drink or something. When I came out I thought I saw 8.4 (normal fill) but it must have shut off at .84 and I was just too tired to notice. Next morning it still showed empty so I thought maybe the gas gauge is glitched or something, I even made an appt. at Toyota for next morning to get it looked at. Anyways I drove to work and that night headed back home part of my 98.6 mile round trip . About 90 miles after the "Fill up" it started stuttering and I thought, oh cr@p I really am out of gas! Anyways I had about 2 miles EV I had regenerated on the way, used it up and then used up most of the regular post EV battery partition to get to a gas station. I filled up 10.5 gallons and was then on my way without a hitch.

    My Bad totally, but nice to know the reserve is very large I guess... Nice to have EV backup as well..
     
  17. bisco

    bisco cookie crumbler

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    sounds like you should have got the 5 hour energy!:p
     
  18. SLOW_RR

    SLOW_RR Member

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    OK, question... Is the ICE in the PIP able to get gas back into the injectors if they run dry? Or does the ICE quit somehow before that happens. I have run Diesel and Gasoline tractors with fuel injection out of gas and it was a major pain of a job to get the lines bled and back working. So how does this work on the Prius?
     
  19. bisco

    bisco cookie crumbler

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    i don't know, but when i ran out of gas in my gen II, the aaa guy shot a couple gallons in and i was good to go.
     
  20. El Dobro

    El Dobro A Member

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    As long as there's power to run the fuel pump and crank the engine, I can't see any problem with starting the car after running out of gas and refilling it. I see people walking around with gas cans all the time on the highway. :D
     
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