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11.9 gallons

Discussion in 'Gen 3 Prius Fuel Economy' started by jwads, Aug 12, 2009.

  1. LakePrius

    LakePrius Special member

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    On the 2010, it would be nice to have an expanded display when you are down to the last quarter of a tank so you have a little better idea of what's left.

    The problem with assuming about 50 miles per pip is that you might find yourself driving in the mountains where you could easily be getting under 20 MPG. On non-hybrid cars, at least in my experience, the worst gas mileage isn't 35% to 40% of the best mileage so it's easier to use some reasonable average mileage. On the Prius, the miles per gallon can vary substantially.

    On a recent trip to Yosemite (in the mountains), I was averaging about 55 miles per pip and drove about 30 miles into the last pip most of which was up hill. When I refueled, it only took a smidgen over 9 gallons, so it turns out I could easily have made it to a gas station with better prices down the road.

    Glad to hear that folks with the 2010's seem to believe that you still have about 2 gallons left when the last pip starts to flash. That would seem to be about the same as what I saw.
     
  2. jwads

    jwads New Member

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    I am on two bars now, distance to empty is something like 103 miles. Will I be good for another 50 miles or so? The distance to empty and the distance driven seem to be about equal, I drive one mile, the DTE drops one mile.
     
  3. Spartane

    Spartane Member

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    Assuming 50 mpg then the answer would be "yes", although I'd be inclined to not push it much past 30 miles.

    There's two other things to keep in mind:

    1. Your electric fuel pump is located inside the tank and it's cooled by the gasoline -- less gasoline could mean less cooling.
    2. As your car ages, any crud that might originate from the filling station(s) where you buy your gas tends to settle to the bottom of the tank. So as long as you leave a bit of fuel in the the tank, that crud tends to stay there and is not forced through the fuel system.

    Anyway, the easiest way to tell is to test it. Drive 20 or 30 miles past empty, fill up, and see how much fuel the car takes. Your reserve is the difference between 11.9 gallons (full tank) and the amount of fuel you put in to fill the tank.
     
  4. alfon

    alfon Senior Member

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    If you fill the tank up to the top of the neck, where you can not possibly get anymore fuel in the tank without it going on the ground, how much will the tank hold.

    I know when the gas pump shuts off on the slow speed you can still put in 2.3 - 2.4 gallons to the top of the neck.

    So does this mean we actually have a 14 gallon tank, from empty to fully full?

    alfon
     
  5. lamontcranston

    lamontcranston Umbra Tenet

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    Probably worth mentioning that topping off the tank can override the vapor recovery nozzles used in many states (such as California.) This releases harmful vapors into the air and that's not in keeping with one of the reasons I bought my Prius.
     
  6. alfon

    alfon Senior Member

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    I understand the fuel vapor recovery system, I am talking in technical terms if the fuel tank is actually 14 gallons from empty to completely full.

    I do not promote filling the tank to the top of the neck on a regular basis.

    alfon
     
  7. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    filling to the top of the neck will flood the vapor recovery system since the filter is located in a bypass line near the bottom of the filler tube
     
  8. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    i am in same situation and my DTE is 118 miles. idepending on what i am doing, i hope to go AT LEAST another 150 miles before refueling. that will only get me to 600 miles. my tank says 63.2 mpg (which is probably around 58-59 mpg) so even if i went 200 miles, that would still leave at least a gallon in the tank.
     
  9. alfon

    alfon Senior Member

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    With the vapor recovery system located in the bottom of the filler tube would gas not get in to that system every time you filled up?

    alfon
     
  10. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    oh no...its in a bypass tube... kinda like a "b". or take a "b" and "p" and overlay them. with the round part containing the vapor recovery cannister. there is two opening for vapor recovery, one at bottom of tube, another at the top but both openings are still above the tank. so only when the filler tube fills up will any fluid get into this area.

    u can actually go a bit up the tube before you hit the cannister... hard to say with a drawing, but guessing a few inches or so.

    **edit** tank update. sitting at 540 miles DTE is 26 miles, last bar started blinking at 526 miles. i probably wont push it much past 600-650 miles...

    crazy?? what u think?
     
  11. cmalberto

    cmalberto New Member

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    Please carry your cell phone with you just in case. I think you will be fine though.

    --Mickey
     
  12. LRKingII

    LRKingII New Member

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    Or a gal can of gas in the back. :D
     
  13. Spartane

    Spartane Member

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    Bob says about 2.15 gallons from flash, so let's work the numbers:

    1. Assume 50 mpg: 50 * 2.15 = 107 miles. So 526 + 108 = 634 miles.
    1. Assume 55 mpg: 55 * 2.15 = 118 miles. So 526 + 118 = 644 miles.
    2. Assume 60 mpg: 60 * 2.15 = 129 miles. So 526 + 129 = 655 miles.

    Based on the above numbers, I'd say that 600 miles is likely OK, but 650 appears to be extremely risky since it looks to me like your actual mileage is very close to 55 mpg, and you would run out of fuel at about 645 miles.
     
  14. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    ya, now, i wished i would have tracked this more often, but on my 3rd tank, i was out of town and drove several miles past DTE and was pretty sure DTE was right at 565 miles which it just about is on this tank as well. anyone else notice that? or just a coincidence?

    sitting at 63.? mpg...hmmm?
     
  15. fuzzy1

    fuzzy1 Senior Member

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    And don't try it on one of those stretches of roads with no gas available to 100 miles, and no cell phone service.