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Featured Empty Tank Not Empty?

Discussion in 'Gen 4 Prius Fuel Economy' started by PriusPeep, Nov 23, 2024.

  1. PriusPeep

    PriusPeep Member

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    My 2017 Prius has a gas tank with an 11.3 gallon capacity, according to Toyota specs.

    Multiple times over the years I have waited until I have zero bars on the fuel indicator. I want to learn the single-tank range of my Prius and compare the impact of the weather/temperature.

    When I fill up I always get about 9.5 gallons. I have never filled up and reached 10 gallons on the gas pump display.

    Does Toyota purposely set the fuel tank gauge to display empty when there are actually more than 1.5 gallons remaining? That means you can drive about 75 miles after Prius is “empty.”

    Is it a safety precaution and/or a law?
     
  2. ColoradoBoo

    ColoradoBoo Senior Member

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    Yes, I think Toyota does leave about a 2-gallon buffer on their tanks.
    But be careful letting your tank get low, especially in the winter. Water rises to the top when it's in gasoline. So if you use up the gasoline any water will then be inside the small gas line and what does water do when it's cold? It freezes and then your car is not going anywhere.
    This happened to me here in Colorado a while ago when we were having a bellow-zero spell. Now, I never EVER let the tank get below 1/4 in the winter.
     
  3. PriusPeep

    PriusPeep Member

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    Great practical tip.
     
  4. Trollbait

    Trollbait It's a D&D thing

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    Don't think it's law, but is a safety precaution. Most manufacturers have the low fuel light come on when there is a gallon or so in the tank. So E is never fully empty. Then variations in the pump shut off switch, sloshing of the fuel while going in, and angle of the car when filling could lead to getting a short fill at times. Plus the listed volume counts the low point where the pump sits, and that only gets drained when fuel emptied until stalling.

    With E10 you don't need to worry about freezing fuel. Ethanol is an antifreeze, and keeps any water mixed with the gasoline. As long as excess water doesn't get into the tank. Note water is heavier than gasoline, but the fuel pump draws from the bottom of the tank.
     
  5. hill

    hill High Fiber Member

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    E10 tends to turn to Varnish faster than alcohol-free fuel. Also (& biggest concern we have is) where a partly empty tank allows for condensation to form. Then you have another issue to deal with.
     
  6. bisco

    bisco cookie crumbler

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    why are we in the news forum?
     
    Mendel Leisk likes this.
  7. PriusPeep

    PriusPeep Member

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    After I posted I realized that I probably should have chosen another category. If possible, please move the discussion.
     
  8. Mendel Leisk

    Mendel Leisk Book Cover Judge

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    You can use the "Report" button below your initial post, ask the moderator.
     
  9. PriusPeep

    PriusPeep Member

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    Thank you. I made the request.
     
  10. hill

    hill High Fiber Member

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    I'd give $100 to 1 odds the request will be much much faster than a request from the Prius chat store

    .