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Gas gage Question

Discussion in 'Gen 1 Prius Plug-in 2012-2015' started by rock87, Mar 20, 2014.

  1. Allannde

    Allannde Just a Senior

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    The computer solution for a low battery is to start the ICE for charging it. No petrol, no start the ICE to charge. Your owner's manual warns you not to do this. Perhaps the computer will shut the car down when there is no petrol left. If it does not, you could be in deep. This is a pretty high stakes risk as you point out.

    The simple solution to prevent this is stop and fill up when the "guess gauge" starts to blink.
     
    #21 Allannde, Jul 4, 2014
    Last edited: Jul 5, 2014
  2. rxlawdude

    rxlawdude Active Member

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    I seem to recall in the old Yahoo forum for 2g that people that ran out of gas could get about 1-2 miles off the battery, but don't recall hearing anyone who permanently toasted it. Totally agree, don't run out of gas to tempt fate!
     
  3. Okinawa

    Okinawa Senior Member

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    Why run it until it is that low? Just fill it up at half a tank or so. No point in creating unnecessary problems for yourself.
     
  4. fuzzy1

    fuzzy1 Senior Member

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    Fill up at half a tank? I hate paying an extra $0.50/gallon just to keep the gauge in the top half when cheaper gas is easily within reach of the remaining tank.

    Perhaps my feelings are also colored by experiences from the fuel shortages of the 1970s, the OPEC oil embargo of '73 and another crisis with rationing later that same decade. And by a later event where the clerk at the only area station still open at that particular holiday hour demanded a 'pump unlock' surcharge equal to a half tank of fuel.
     
  5. The Electric Me

    The Electric Me Go Speed Go!

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    My experience which has led to my usual fill protocol in regards to The Prius, is that the gauge and DTE is very conservative. For me, the blinking last Pip serves only to remind me to pay attention to DTE...and then DTE once reached serves as THE reminder to refill. But I don't panic, even when the DTE reaches zero. I refill...as soon as convenient. Even going to DTE zero, and slightly beyond I have found The Prius still has a gallon plus more gas.

    I refill relatively soon once the DTE reaches zero, simply because I don't want to risk running out of gasoline. BUT, I feel driving to DTE zero, and even slightly beyond in no way puts me in that position.
     
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  6. LA2014Prius

    LA2014Prius Junior Member

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    I rarely wait till the fuel flashing to add gas... Just wondering... When DTE reaches zero, does it show -1 -2 -3 -4 after that?
     
  7. Okinawa

    Okinawa Senior Member

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    How do you figure you are paying $.50 per gallon more by taking a chance of running out of gas versus filling up at half tank down for example?
     
  8. fuzzy1

    fuzzy1 Senior Member

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    Nope. It stays at 0.
     
  9. fuzzy1

    fuzzy1 Senior Member

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    I often travel through areas were sparse population and sparse fueling opportunities produce little price competition. A blanket rule to refill at half a tank would too often require paying high tourist trap or middle-of-nowhere prices.

    A little bit of ability with math, planning, and pre-testing to approximately calibrate the fuel gauge, go a very long way in avoiding those high prices. I realize that some folks have none of those skills. Let them pay those high prices, but I'm not going to take any grief for their deficiencies.

    On my common long trip (400 miles) to visit an aging parent and assist with his farm-ranch work, the best fuel prices are near my home, and 360 miles down route. The price difference patterns along the route vary, but when I traveled it most recently (Wednesday), the good price was $3.61, while the going rate in a very long stretch around the half tank point was $4.09. OK, that is just a 48 cent/gal difference, not 50, but you should get the point.

    Another example is a scenic loop from here across the Highway 2 one way, and the North Cascades Highway (#20) on the return. Take two or three days and several side trips for a 500 mile total. Filling up at half a tank means refilling in the tourist trap town of Winthrop, where what used to be the sole gas station was easily 50 cents higher than home even when gas was in the $2 range. Increasing competition from Twisp and Mazama has since shrunk that premium, but not eliminated it.

    On my long vacation road trips of the past five years, including many sparsely served areas of the American West, gasbuddy.com has revealed numerous cases where it was worthwhile to plan refills far far in advance. Sometimes this meant filling up with 6 bars remaining, sometimes pushing down to 2 bars or 1 flashing bar. Numerous other factors are taken into account when deciding how far down to allow the gauge to fall.

    My memories and experiences from the 1973 OPEC Oil Embargo, and that price gouging clerk, have been described in other threads. But when airline pilots know their fuel range to within about a five minute uncertainty, I'm just cannot leave a vague two hour uncertainty in cars 'just because'.
     
    #29 fuzzy1, Jul 6, 2014
    Last edited: Jul 6, 2014
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  10. The Electric Me

    The Electric Me Go Speed Go!

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    This.

    I actually think I could go a considerable distance once the DTE reaches zero...but I'm not driving The Prius to play games. So once I reach zero, I just go fill up.
     
  11. rxlawdude

    rxlawdude Active Member

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    Actually, there's even a better (er, more scientific) way for those who are diligent about filling the tank thoroughly during refueling. (And of course, the PiP is infinitely better than the 2g Prius, with the fuel bladder and "guess gauge.")

    One of the consumption screens (the one that shows % of miles traveled on EV and on gasoline) shows the integer value of gasoline used. I've found the blinking fuel segment comes on when the aforementioned display shows "8" gallons consumed. Of course, this could be 8.000001 gallons or 8.999999 gallons, but that's not salient.

    If I know I have a 10.6 gallon tank and I'm careful to fill it all the way up when refueling, I know there is at least 1.8 gallons remaining till the display shows "9" gallons consumed. When it shows "9" gallons consumed, it's time to find fuel, stat. (And even then, there should be at least 100 more HV miles of range in worst-case scenarios.)

    With over 200,000 Prius driven miles including the 2g with a finicky bladder and "guess gauge," I'm confident this practice is safe.

    I'm half expecting someone to berate me for "overfilling" the tank, claiming it could foul the carbon filter canister. Again, this wasn't an issue with the '04 that now has north of 275K miles on it, and I certainly don't expect it's a problem with the 3g.
     
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  12. Allannde

    Allannde Just a Senior

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    There is a lot which makes sense in what you say .

    Filling the fuel tank is not a scientifically precise thing to do. The float in the gas tank can stick causing the gauge to read incorrectly, the gas delivery pump may not be as accurate as you think, the volume of the gasoline changes with the temperature (it contracts when cooler and expands when it warms), there can be water in the gasoline from condensation in the tank at the gas station, different nozzles click off at different times and the gasoline can be old from sitting, especially in the out of the way gas stations. When I am able, I go to the same gas station and the same pump to fill (which is most of the time). When I can't, I find the nearest Chevron station to fill the car. It works out just fine.