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800 mile attempt on one tank

Discussion in 'Gen 3 Prius Fuel Economy' started by a64pilot, Sep 20, 2009.

  1. bps

    bps Active Member

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    a64pilot,

    Sweet! Congrats on the 800 mile tank!!! No milk it for all it's worth and see if you can squeak out 900 miles on this tank. Doubtful, but maybe possible...

    Bryan
     
  2. a64pilot

    a64pilot Active Member

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    It's around 850 now and going to die any minute, I think. The pip has been flashing for a little over 100 miles, and if Bob is right (I'm sure he is) it should die right at 120 to 130 miles after it first started flashing. That would be in about 10 miles or so. I started to just drive it this afternoon till it quit, but didn't. I expect it in the morning. No way anything near 900 is possible now, but the goal was 800, so I'm happy.
     
  3. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Actually you and Wayne ('firengineer') are the only two who have approached running out of gas in the ZVW30. Wayne hasn't reported driving to fuel exhaustion ... unless I missed it.

    The irony is we both fly (I'm not current) and we're likely to be the small set of those who with attention to detail, perform the "forbidden" experiment. But I think you share my curiosity about 'what happens when the car finally runs out of gas ...'

    BTW, don't rule out manufacturing differences between our respective cars. I can only measure the car in our driveway.

    Bob Wilson
     
  4. a64pilot

    a64pilot Active Member

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    Well, I set out a little early this morning to "get er done", but I think it's the energizer bunny or something. It's at 877.1 and still running. I had to get to work. Surely it will run out on the way home for lunch. 4.2 mile trip
    Bob, I have been wanting to go up there to here Moontown Airport 3M5 for some time. I hear it is a cool place for tail draggers to hang out. Apparently last weekend was the time to go.
     
  5. a64pilot

    a64pilot Active Member

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    OK,
    First running out of fuel is in my opinion a complete non event. Nothing to fear. Your driving along and if your paying close attention you can feel a little surge as it runs out, but it's so slight it would be real easy to miss. Anyway the car continues on as if nothing has happened, the real clue the ICE is "dead" is that you can accelerate well past the center part of the HSI and your MPG read out remains pegged at 100. I just maintained speed in the 40's, drove the .6 miles to the station and refueled. Didn't bother with the fuel tank I had in the back.
    Once you re-fuel it, you simply push the ready button and when you drive away and the HSI passes the middle, the ICE lights off just as if you hadn't run it out of fuel, I expected a slight delay at least before the ICE "caught", but it was completely normal.
    Unlike a "normal" car, the Prius didn't lose power steering, power brakes or even the AC, but I didn't run the traction battery down enough for that. No MIL (malfunction indicator lamp), no DTC (diagnostic trouble shooting code), nothing.

    Car ran out at 892.2 miles, it was an additional .6 miles to the filling station, so the pic I have says 892.8, I think. It took 11.8 gls. to the auto shut off with the hose set on the first click. It took 13.5 gl. to top it off though, so 892.2 div by 13.5 = 66.08 actual with 68.0 computed. This is confirmed pure gas, no ETH as I use it in airplanes and your not allowed to have any ETH in fuel used in airplanes.
    I'll post the pic tonight at home, I'm at work now.

    I should have "milked" it 900 was within reach, but that's for somebody else.
     
  6. bwilson4web

    bwilson4web BMW i3 and Model 3

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    It was except for the cumulogranite weather in the early morning.

    Bob Wilson
     
  7. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Cool!

    How do you get to 13.5 from 11.8? I just wait 5-10 seconds for the foaming to end and then fill to the next click. I've long suspected more could be put in but I'm also cautious about the canisters getting saturated. Using the second click, I'm seeing 12.1 gallons BUT that is with my wife's car.

    Bob Wilson
     
  8. a64pilot

    a64pilot Active Member

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    I just slowly top it off until I see fuel in the neck with the level slowly going down. I'm a decent mechanic, if you saturate a cannister it will trip the MIL, you download the DTC that tells you the cannister is bad, you replace it, but I have never, ever had that happen, but it's no big deal if it does. All fuel tanks are manufactured with an air space for expansion, it's a bubble in the top of the tank. Where topping off a tank could theoretically get you in trouble is you top off your tank with cool fuel from the underground tank and let the car sit in the sun, and the fuel expands into the expansion bubble and ruins the cannister. But if you drive quite a bit before putting the car up, you eliminate this potential problem. It's merely a matter of understanding the potential problem and putting controls in place to mitigate the problem. Simple risk assesment / risk management.
     
  9. a64pilot

    a64pilot Active Member

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    I think there is a pancake breakfast or something similar monthly, wanna meet and do a little flying in the Maule?
     
  10. bwilson4web

    bwilson4web BMW i3 and Model 3

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    That makes this more practical:
    1000/13.5 = 75 MPG vs
    1000/12.1 = 82 MPG
    Since I use my NHW11 for commuting and my wife's ZVW30 for errands, it is entirely possible to 'cherry pick' my drives and maintain 75 MPG for a series of errands and weekend 'drives.'

    FYI, I'm taking the wife's car in for service on Saturday and will be changing the transaxle oil as well as engine oil with samples to send out for testing. They plan to rotate the tires and I'll measure the tread depth before it goes in the shop. Then Sunday, I'll ask Firestone to measure the alignment so I can compare it to "as delivered."

    On Friday, I'll re-run my benchmarks and we'll have a pre-service and post service set of numbers. <grins> Then I'll run the tank dry to test the fuel pump current for a real "out of gas" light and then fill-up with straight gas.

    My previous three tanks:

    • 67.2, 67.1 and 64.0 MPG
    It looks like with careful planning and "cherry picking" my drives, a 1,000 mile tank is doable. ...

    Bob Wilson
     
  11. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Yes and no. Yes because I love to fly ... no because I'll have to start flying again. <GRINS>

    Send a PM and let's do it.

    Bob Wilson
     
  12. a64pilot

    a64pilot Active Member

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    Would you believe I don't know how, but I do know how to answer one:doh:
     
  13. a64pilot

    a64pilot Active Member

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    Promised picture of the dash

    One of the Maule

    And one of the "flea" we went to fly last weekend, My son is in the flea
     

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  14. Indyking

    Indyking Happy Hyundai owner...

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    In some countries, you can get a fine (actually an expensive one), if you run out of gas because of its negative impacts on traffic flow.

    Humm... I'm thinking pure gasoline with no ETOH.... that explains the high MPG.
     
  15. a64pilot

    a64pilot Active Member

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    Yes, in Germany on the Autobahn for example you can. But this isn't Germany and I wasn't on any kind of divided highway. Actually one of the biggest fines you could get was by being rude. And then there is the "drive right law". Too bad we don't have German laws. And if you bothered to read the post, I didn't even slow down, much less impede any traffic, I continued on the the service station just below 46 MPH because I didn't want to overspeed anything. Speed limit is 45 MPH there. If the car had quit, I would have simply put on the right turn signal and pulled into one of the many parking lots on that section of road. I knew what I was doing, there was a "plan".
    Pure gasoline as opposed to E10 may result in as much as a 3% increase in fuel mileage, 1 to 3% in re-formulated or oxygenated fuels most of us burn if not E10. So if you mean a 1 to 3% increase in mileage, your correct. I think the pure fuel is the reason my computed and calculated mileage are closer than usual.
    Running E10 my mileage should have been about 64 or so instead of 66. Not a whole lot of difference.
    You should know that E10 MAY contain up to as much as 10% ETH, it may be 0%, but it will not be more than 10%. Since the drop in oil prices, actual E10 is unusual, at least down here. Pure gas is pretty common, even when the label say's E10. Now that will vary from state to state, I believe many states have mandated E10
     
  16. Indyking

    Indyking Happy Hyundai owner...

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    :eek: Are you OK? I was not trying to be rude, maybe my post came in a bad time? Go figure... :eek:

    I only pointed out some facts... which are absolutely true. I did not say you were trying to ruin the traffic pattern, neither did I try to guess how much the MPG hit is with ETOH-added gas...

    Chill out... :cool:
     
  17. a64pilot

    a64pilot Active Member

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    Yes, but they weren't relevant were they?

    The sun sure is bright if you stare at it isn't it?
     
  18. alfon

    alfon Senior Member

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    Oregon is mandated for 10% Ethanol. I believe there is a 5-8 % decrease in MPG when used.

    Pure regular gas is nearly impossible to get as quite a few states are mandating Ethanol.

    I bet it probably takes 1 1/2 gallons of diesel to make a gallon of Ethanol. Common sense does not apply.

    alfon
     
  19. Indyking

    Indyking Happy Hyundai owner...

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    Perhaps the facts applied to you... you were judging yourself, not me... it was not what I intended to do…
     
  20. Indyking

    Indyking Happy Hyundai owner...

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    Disagree! It is more like what Alfon mentioned (5-8% MPG hit in ETOH vs. pure gas). My brother has done the test himself in Brazil, where most cars are flex ETOH and gasoline. He tested ETOH, pure gasoline, and Brazilian gasoline (which has 20% ETOH) in his car and found an increased FE of around 15-20% with pure gasoline vs. gas with 20% ETOH and close to 40% with pure gasoline vs. 100% ETOH.