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Prius Fuel tracking

Discussion in 'Gen 2 Prius Technical Discussion' started by jkm750, Nov 19, 2006.

  1. jkm750

    jkm750 New Member

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    I am writing this because I feel the fuel gauge that Toyota is totally useless. I am hoping someone who has done some programming on the prius can help out. I think it would be more useful is there was a gauge that told you how many miles you had till you ran out of gas verses a blinking square that just makes you think you are running out of gas but still have about 100 miles to go. I have looked in several places to see if anyone has asked this question. I am surprised with all the technology that they so not have a glass like cockpit like in airplanes. I love the car and all it does but feel these would be huge improvements to the car for us who like to see gauges.
     
  2. john1701a

    john1701a Prius Guru

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    <div class='quotetop'>QUOTE(jkm750 @ Nov 18 2006, 11:16 PM) [snapback]351597[/snapback]</div>
    You are far from the first person to ever want to push beyond the standard "blink at 8" capacity. Toyota intentionally programmed it that way to help deter owners from running out of gas... which was much more frequent in the old days when the gauge did in fact wait longer before blinking.

    Even if you were only getting 40 MPG, indication to refill would be past the industry accepted 300-mile threshold. So you'd have to come up with a darn good argument to want more. To this day, no one has. Protecting the battery-pack from accelerated aging has always been a higher priority. Sorry.
     
  3. jkm750

    jkm750 New Member

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    I am writing this because I feel thats the fuel gauge that Toyota provides is totally useless. I am hoping someone who has done some programming on the prius can help out. I think it would be more useful if there was a gauge that told you how many miles you had till you ran out of gas verses a blinking square that just makes you think you are running out of gas but still have about 100 miles to go. I have looked in several places to see if anyone has asked this question. I am surprised with all the technology that they they have in this car that they have not incorporated a glass like cockpit like in airplanes with all the gagues. I love the car and all it does but feel these would be huge improvements to the car for us who like to see gauges and what is going on inside the car. Maybe my alternitive is the can232. I was justreading that and think I am going to order that and put it on the touch screen. sorry the original post I did half asleep. B)
     
  4. panda

    panda Junior Member

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    <div class='quotetop'>QUOTE(john1701a @ Nov 19 2006, 02:16 AM) [snapback]351622[/snapback]</div>
    Hey, nice web site, John. Are all those Prius owners your family/friends?

    We just bought our 2006 Prius on November 5th. I have driven over 900 miles since then, and each time I get in the car I find myself either thinking or saying to myself; "I *love* this car!"

    I have filled up twice now, and what a wonderful experience that was.

    The first time I filled up, there was 2 squares showing and then when I got to the gas station there was only 1 square showing. I read the manual about *not* running out of gas, and I got nervous. The second time I filled up I had 3 squares showing. What is the 'safe' limit? 1 square? 2? 1 blinking?

    Thanks for the input!

    Pat
    a
    n
    d
    Arlene
     
  5. sgails

    sgails sgails

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    <div class='quotetop'>QUOTE(jkm750 @ Nov 19 2006, 12:16 AM) [snapback]351597[/snapback]</div>

    I am sorry but I don't see why the fuel gauge is a big deal. We are adults and responsible for filling our tanks. Why do you want to get down so low anyways? I always fill mine when 1/2 empty or just below. It's not good to run your tanks so low on gas with winter coming. If in doubt fill it up!!
     
  6. jstack

    jstack New Member

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    If you are that low it would be hard for anyone to acuratly predict how far you could go. If it was up hill or you drive like a teenager using moms gas it could be 30 miles. If you drive smart like me it could be 200 miles.
    All the prius can do is start to warn you. If you chose to wait until the last mile that's your choice.
     
  7. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    i think the blinking bar is a safe way to fill as long as you are planning to stop within a few miles or so.

    with CANVIEW you have the additional information that breaks down the tank into 2½% increments. the blinking bar on the 2004 started at about 12% so there was quite a bit left in the tank. some here reported going more than 100 miles (not realistic or recommended) before refueling.

    but there MAYBE growing evidence that the newer models (probably 06 and up) may have the blinking bar starting at 6%. so i recommend the blinking bar OR when its convenient at 2 bars. even at the onset of two bars most will still have 400 miles and most likely more.

    on my Corolla, 400 miles was obtained about 3 times in the 170,000 that it was in my family
     
  8. walt

    walt New Member

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    <div class='quotetop'>QUOTE(jkm750 @ Nov 19 2006, 12:16 AM) [snapback]351597[/snapback]</div>
    The car has a variable sized bladder, not a fixed capacity tank. It doesn't know how much gas is left!

    Think about your trips and when you might want to get gas at two pips.
    Get gas "soon" at one pip.
    Get gas NOW! at blinking pip.
     
  9. jkm750

    jkm750 New Member

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    It is not that I am running the car out of gas or even close to that. As I like to see what is going on with the car the bar gauge is a useless device. I track my gas by miles driven. I is nice to know how many miles I have left till I run out. Kinda like when your friends with the big trucks can see that you can go 400+ on a tank of gas. My buddy has a Dodge ram that tells him DTE (distance till empty). Like I said the digital bar graph is far harder to read than an analog gauge. Toyota did so much to impress people on how well the car gets on gas millage and then they stick a digital bar graph in the car. A better use of that space could just be you have X amount of miles to go. I am sure there are other people out there that would agree.
     
  10. Frank Hudon

    Frank Hudon Senior Member

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    check the gas tank in the wife's 2k4 Prius.
     

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  11. eagle33199

    eagle33199 Platinum Member

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    <div class='quotetop'>QUOTE(jkm750 @ Nov 19 2006, 03:48 PM) [snapback]351792[/snapback]</div>
    We definitely agree and would like to see one, but as it's been pointed out it's not something you can add. Think of it this way. you're heading home from work one cold, winter day, and because you have a 40 minute commute, the car is fully warmed up. you pass the station by your house because the reading says you can still get 30 miles out of it, and it's your daughters birthday (or something), so you figure you'll just fill up the next morning. Well, the next morning arrives, and you start out... instead of the 60 MPG you were getting when you got home, your instantaneous mileage is now only 10MPG! So you get 1/6 the distance you had thought, or only 5 miles, out of what was left in the tank. Suddenly, that gas station looks like it's a long ways away.

    The DTE on the truck is a different story. when you only get 10 MPG on average, you can estimate the DTE a lot easier - the mileage doesn't vary nearly as much. So what if you're getting 12 when going home and then only 8 during warm up the next morning? that 30 miles the previous night would then be 24 miles, which is still close enough to be plenty.


    FWIW, i think the gas gauge does a decent enough job. It provides a nice visual clue as to when you're running low, and even if i could have gone another 100 miles after it starts blinking, i'll most likely be filling up before then anyways (usually fill up 9+ gallons with 1 pip left, hardly ever see it start to blink).
     
  12. jrfaris

    jrfaris Member

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    <div class='quotetop'>QUOTE(walt @ Nov 19 2006, 12:22 PM) [snapback]351770[/snapback]</div>
    This is the critical point. All of the other discussion applies but when there is no way to accurately know the volume of gas in the tank, all predictions of when it will empty are just guesses, regardless of how "precisely" they are calculated...
     
  13. jkm750

    jkm750 New Member

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    Thats cool. it was just something that I thought would be cool but now understanding that there is a blatter vs. a regular fuel tank and different equations to figure. I was just something to think about.
     
  14. riksvag

    riksvag New Member

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    So - we know that the gauge doesn't show remaining fuel correctly, it's even said here that the car doesn't even know itself, since its a bladder. Then why did Toyota put the damned thing there for me to see it? Why didn't they put in a weight-measure thing or something instead?

    After refuelling, I can drive km after km and it still sits at full tank. Then the bars disappears faster and faster, and at two or one bar, again, I can drive km after km with no action on the gauge. Its about as correct as the progress bars when installing applications in my XP.

    Same goes - by the way - for the speedometer. It's about 10% wrong (driving at 100 Km/h on the meter is only actually 91 Km/h). Maybe this is only a EU feature.

    Anyway, my car is a 2007 (just arrived from Japan), and you might think that a car that new would have more correct gauges.

    This, and the fact that the NAV-destination/BT-phonebook/MP3-list is locked during driving, is one of the most annoying things with my car. The rest is of course fantastic!
     
  15. hobbit

    hobbit Senior Member

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    What's "WOTmode" ?
    .
    _H*
     
  16. FreshAirGuy

    FreshAirGuy New Member

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    <div class='quotetop'>QUOTE(jkm750 @ Nov 20 2006, 04:43 PM) [snapback]352205[/snapback]</div>

    The fun is just starting. Good luck figuring how many miles you've travelled on a gallon of gas. As they say on Priuschat.com "enjoy the ride."
     
  17. Frank Hudon

    Frank Hudon Senior Member

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    <div class='quotetop'>QUOTE(hobbit @ Nov 20 2006, 04:05 PM) [snapback]352320[/snapback]</div>
    he told me a while ago but I had forgotten so here's his email to me, I've "x" out the names of the people he was working with.

    "Hi Frank, while I was working with xxxx xxxxxxx on that fuel flow issue, it became apparent that there was a definite mode when you pressed the accelerator more firmly, one which did not stop unless you
    also released the accelerator more quickly too. Not knowing what it was, I just called it WOT (wide open throttle) because that is guaranteed to enter it every single time.

    I do not know how it affects fuel consumption, I am guessing the prius detects more rapid accelerator movement and says wow I'd better be prepared for some action as the driver seems a bit anxious right now.
    Who Knows???? But whatever it is, it does exist and you can exit it just by lifting off the accel, even momentarily. xxxx xxxxx says it co-incides with what some call super-stealth. Beats me. I hoped someone smarter would figure it out and I could give it a different name. But I can't pretend it doesn't exist. And its quite repeatable. It also may be quite important because its one of the few CAN messages that Toyota assigns high priority to.
    Norm"
     
  18. Fatfenders

    Fatfenders New Member

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    <div class='quotetop'>QUOTE(sgails @ Nov 19 2006, 10:01 AM) [snapback]351657[/snapback]</div>
    Why? :huh:
     
  19. GeronimoPFudgemuffin

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    I figured it was because the M1 Abrams has on operating range of less than 300 miles, and you wouldn't want to get caught out in a snowstorm in one.

    GeronimoPFudgemuffin (who figures there's more fuel tank condensation during the summer, but it won't freeze like it could during winter, but since it doesn't get that cold here, I'm at a loss)
     
  20. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    well would you rather walk to gas station on a nice pleasant summer evening or during a nasty winter snowstorm....

    that alone is enough for me.