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Q about the gas tank

Discussion in 'Prime Main Forum (2017-2022)' started by EyePrime, May 26, 2018.

  1. Mendel Leisk

    Mendel Leisk Senior Member

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    So you're saying, from the first shut-off of the pump, and this would be when the fuel filler pipe is already partially filled, and gas is starting to kick back, you're able to squeeze in an extra 5 liters of gas? That's assuming 5 liter per 100 km consumption? That's say from here to here:

    upload_2018-5-27_9-14-34.png

    I've heard filling to the neck may mess up the Evaporative Emission Control system, leading to costly repairs. May or may not be the case, but I'd rather not find out the hard way.
     
    #21 Mendel Leisk, May 27, 2018
    Last edited: May 27, 2018
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  2. Oniki

    Oniki Active Member

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    How about just fouling up the emissions control as a reason to avoid that behavior ?

    I gather that the specific problem is spillage into the activated charcoal container.
     
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  3. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah I was reading a bit, seeing that the cars are pretty idiot-proof, but stuff can happen. For example: you fill it to the neck while level and everything's barely ok, but then drive through a banked turn, or park on an incline, and gas makes it into the charcoal canister.
     
  4. ClemsonSteve

    ClemsonSteve Active Member

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    Exactly
     
  5. Prime8

    Prime8 Member

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    When DTE reaches zero, there appears to be one gallon of usable fuel left.

    When DTE reaches zero, I reset a trip odometer. When the trip odometer and and MPG are the same number, is about where I run out of fuel(1 gallon). It will continue to run on electricity only. I have not run it out of both fuel and electricity.
     
  6. Mendel Leisk

    Mendel Leisk Senior Member

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    Yet...
     
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  7. Prime8

    Prime8 Member

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    Correct.

    I do not have plans to test that edge of the envelope. I suspect that the car will cease all forward motion.
     
  8. Oniki

    Oniki Active Member

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    Or never, if he keeps electricity in reserve. After all, how many people find themselves in places where a petrol station is not within the next 15 - 20 miles ?

    I don't see the advantage to the behavior but it strikes me as fairly harmless: Perhaps some inefficiency related to CHARGE MODE use, and the possibility of fuel pump damage from over heating if it becomes a habit.
     
  9. Prime8

    Prime8 Member

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    I travel between 3 states and can see upwards of 50 cents per gallon variation, so I occasionally push that last gallon envelope with electricity held in reserve for the end. The GOM is much more accurate near 0 for electricity, than gasoline. I only do that when the on the fly math indicates that I will reach Costco with some electric reserve(6 miles remained last time). If I had not tested the range of the gas, I could not do that math. Folsom is currently $3.35, and Carson City is $2.99. I can buy lunch at that Costco for that difference.
     
  10. Oniki

    Oniki Active Member

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    I understand, but I prefer to just put in one gallon at an expensive place if I am feeling stingy.
    Or, in the case of giving myself ~ 20 miles more driving like your EV reserve, about 1/3 gallon.

    What kind of lunch can you get for 15 cents ? And is that savings really worth leaving your fuel pump unprotected from over heating ?
     
    #30 Oniki, May 27, 2018
    Last edited: May 27, 2018
  11. Mendel Leisk

    Mendel Leisk Senior Member

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    It's gone below half, I fill it up. Don't even look at the price. :p
     
  12. bwilson4web

    bwilson4web BMW i3 and Model 3

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  13. Oniki

    Oniki Active Member

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    That is because you are desensitized to high prices; and IIRC there is very little variation between stations anyway in your neck of the woods :p
     
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  14. fuzzy1

    fuzzy1 Senior Member

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    That would be everyone who traverses the TransCanda Highway, I-70, the Banff-Jasper Icefields Parkway, US-395, US-50, US-6, US-20, US-12, and I'm sure plenty more.
     
    #34 fuzzy1, May 28, 2018
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  15. Oniki

    Oniki Active Member

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    Heh. And here I thought I live in a rural place
     
  16. Tideland Prius

    Tideland Prius Moderator of the North
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    I usually do that when the car is new and the gas tank doesn't have crud at the bottom. I've gone 100km on the blinking light in the Gen 3 with 4-5 ltires to spare. The wiggle room is smaller on the Gen 4/Prime because instead of the usual 10 litre warning that Toyota gives, I think Toyota kept the same threshold (after 40 litres of use) but shrunk the tank size from 45 litres to 43 litres. Which means now you have 7 litres in reserve instead of 10.

    If I had the cahunas, I would've broken 1,000km on the tank. Alas, I didn't run to run out of fuel on the main street (it was the middle of the week) so I stopped at 955km and that remains my record for the Gen 3.
     
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  17. triggerhappy007

    triggerhappy007 Active Member

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    It's not a 15 cents difference. They mean filling up a full tank at $2.99/gal vs $3.35/gal. That's almost $4 = lunch at Costco.
     
  18. Oniki

    Oniki Active Member

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    You are missing the point. No reason to "fill up the tank" at the expensive station. You are allowed to buy as little as you please, so I calculated the battery reserve equivalent.
     
    #38 Oniki, May 28, 2018
    Last edited: May 28, 2018
  19. triggerhappy007

    triggerhappy007 Active Member

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    I see what you're saying about buying a half gallon at the more expensive station first. But we were comparing about getting a full tank. You were the one that brought up 15 cents. I agree it's bad for your fuel pump if it's very low or runs out of gas. The Prime has about 1.7 gallons left when the light comes on. That will get you about 50 to 75 miles before you need to fill up.
     
  20. Oniki

    Oniki Active Member

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    Actually, the discussion was about running the tank to empty to reach less expensive petrol. I'm pointing out that his solution is worse and more risky than just taking on a fraction of a gallon of more expensive fuel en-route.

    The full tank requirement is a false choice.