[WARNING] Running out of gas (Gen III)

Discussion in 'Gen 3 Prius Main Forum' started by bwilson4web, Jun 26, 2009.

  1. Celtic Blue

    Celtic Blue New Member

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    The bold proves my point. It is reasonably possible for you to find yourself in a situation where this can occur. Any vehicle that you get into that you are unfamiliar with (including a brand new one) could do this to you. It doesn't have to be my examples specifically.

    In fact, every time you get in your own vehicle there is a possibility of it being out of gas within a few miles despite what you think you know about its fuel condition. Hey, maybe somebody siphoned the tank in the middle of the night. Maybe you have a fuel leak/puncture. (I never would have thought that Caprice could leak so much fuel without it being blatantly obvious...but Texas heat took care of the liquid while I worked; couple that with a faulty sender, the dreaded double failure, and there I was out of gas despite reasonable precautions.) Or consider the possibility that some element of the fuel delivery system fails...it will be the same as out of gas. Ever have a fuel pump fail? I have thanks to an incompetent dealer service dept. messing with a component that was working just fine before they touched it. I had diagnosed it within about 30 seconds of it dying and knew who was responsible.

    Saying it is not reasonable to suppose you will ever have an out of fuel situation is akin to claiming you will never have catastrophic engine failure, or transmission failure, or a flat tire, or a dead battery. There is quite a bit beyond your control. You can take actions and precautions to make such situations unlikely, but assuming that the vast majority of folks who run out of gas are "just asking for it" would be a mistake. Unfortunately it is the very mistake those yelling at us are doing.
     
  2. Celtic Blue

    Celtic Blue New Member

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    Who gives a crap??? It isn't anywhere close to what you originally claimed. Unlike you I'm not going to fabricate numbers. What is the point? You made up a basis to say something ridiculous and counter to your original claim. What, you want a cookie for that???

    Let me be more clear: you are being deceitful and arguing just for the sake of arguing.
     
  3. viking31

    viking31 Member

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    Maybe Toyota should put a large flashing sign on the outside of each Prius when the last pip is flashing stating:

    "Hello, I am mentally impaired and my car has been telling me for over 100 miles and two hours straight I am about to run out of gas. The horns, buzzers, computer voices, flashing gas gauges, and electric shocks delivered to me every minute warning me I am about to run out of gas give me no clue I need gasoline asap. Please direct me to the nearest filling station before I run out of gasoline on the road and get killed!"

    That should do it and stave off those pesky lawsuits that Toyota is bound to lose billions because the Gen III cannot use its battery to get you another few hundred feet (umm, that's after the last pip was flashing for 132 miles) when you run out of gas.

    Rick
    #4 2006
     
  4. yardman 49

    yardman 49 Active Member

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    Maybe we need to look at this from a different angle...

    1) I think that most members reading this would agree that some sort of ability to run in EV at the point that the Prius runs out of gasoline is a good thing (a la Gen 1 and Gen 2).

    2) But if Toyota had never had the "run on EV after gasoline runs out" feature in G1 and G2, would anyone be talking about the possibility of "suing" them for not having it? Most likely not. Most likely this thread would not even exist, because we would have never "experienced" anything else than the Prius simply stopping when it runs out of gas (like every other ICE equipped car).

    3) If we can agree that points 1 and 2 are valid, then why is it that losing the aforementioned ability is tantamount to negligence by Toyota? For whatever reason, they simply did not include that feature any longer. Would it be nice to have it back? Definitely. Can they be forced to bring it back? Probably not.

    I am in the camp that says, "just don't run out of gas". I think that people have to take personal responsibility for their actions, and not expect to always be saved from themselves.


    But I thank Bob for his experiments. When new technology is available, change can sometimes be good. The G1/G2 functionality does seem to fall into this camp. As such, maybe Bob wouldn't mind writing a letter to Toyota requesting that this functionality be restored? Or that it be brought back in a modified form (tied to the SOC), as some have suggested??

    At the very least, it would be desirable that a better warning be given when the car has run out of gas than just the power steering failure. Some sort of flashing of all the pip bars in the gas gauge should work well. This could also be suggested to Toyota.

    At the very least, this thread has been entertaining!
     
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  5. web1b

    web1b Active Member

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    It would be nice if the battery worked so you could drive after running out of gas, but it doesn't, so you need to be more careful.
    I know if it did many people would use it as their reserve and wait until the gas goes dry before filling up then still get caught short of the gas station when the battery didn't take them quite as far as they hoped.

    Just fill up as if the car didn't have a battery to fall back on.
    If the only times people ran out of gas were when the gas gauge failed or the car had a rapid fuel leak, there would be many fewer people running out of gas than there are today.
     
  6. fuzzy1

    fuzzy1 Senior Member

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    With my first car, and the roads I was driving on, this rule would have caused you to run out of fuel. Numerous times.

    That car had short fuel range, ran out above E, and I drove triple-digit stretches with either no fuel stations, or none open along my route during those hours. In the incident that forever changed my handling of fuel range, I began looking for gas with slightly over 1/2 tank indicated, refused the pay the pump unlocking fee with close to a half tank indicated, and sweated to the next known open pump. That was before the widespread proliferation of 24/7/365 stations, but these have not yet befouled all my routes.

    A realistic refueling rule for that car, if applied to my youngest pre-hybrid, would leave an absurd amount of dead weight inside the tank.

    I disagree. Letting your airplane run out of fuel is far dumber than doing so with a car.

    You won't go the last hour on your tank. My cars have displayed more than a two-hour spread between the most optimistic and pessimistic fuel gauges. Do common airplanes have that much fuel uncertainty?

    I thank Bob for locating and reporting the bottom of his fuel tank. And after dealing with a number of non-empty fuel system failures in cars of my own, the spouse, and a few other relatives over my lifetime, I'm also glad that he reported how the P-3G behavior differs from expectations.
     
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  7. CAR4TWO

    CAR4TWO New Member

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    This whole discussion is absurd. My airplane carries 39 gallons of fuel and when I have one hour left, I have 8 and half gallons. In one hour, I have 120 miles to find an airport with gas. The FAA requires I have 30 minutes of fuel at my destination during the day and 45 minutes of fuel at my destination at night. Using those guidelines, we never run out of gas.

    I am always local when I take my cars to 1/8th tank and I do that just to burn all the old gas out of the car before replacing it with fresh gas.

    I don't think running out of gas is a huge problem for American drivers. In this discussion, we are trying to make it so.

    You too should have enough gas to get to your destination plus 30 to 45 minutes whether you are driving a car for flying an airplane.

    You are trying to turn this into Rocket Science and it's all about simple fuel management.
     
  8. CAR4TWO

    CAR4TWO New Member

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    Fuzzy one, even the airlines fly with the same fuel rules that us Private Pilots use. How many airlines run out of gas before they get to their destination? None. Our gages are very precise in that they tell us in gallons what is remaining in the tanks. Airlines deal in pounds of fuel onboard. I carry 239 pounds of fuel. At 2,200 rpm, I burn 34 pounds per hour. I have 7 hours of fuel onboard and no bathroom. You figure it out. If I'm in a hurry, I can burn 52 pounds per hour giving me over 4.5 hours of fuel onboard and I still have no bathroom. In three hours, I can travel 360 miles and still have 78 pounds of fuel onboard, which is enough to take me another 180 miles in a straight line. Gosh, I love to fly. It's the preciseness of of it all that I love so much.

    I think that if your gas gage is flashing, you should proceed directly to a gas station and top it off. If you practice good fuel management, you will never run out of gas.

    If you do run out of gas, you pull over to the side of the road. Put out your emergency flashers, that is scantily clad guy and gal sitting in a chair to slow the traffic while you call AAA to bring you a gallon of gas. Pilots do know how to manage their fuel flow.
     
  9. efusco

    efusco Moderator Emeritus
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    What keeps coming to my mind in this thread is how attitudes about how "I" would never run out of gas and "Nobody" should run out of gas. But the reality is that people, even smart conscientious ones do run out of gas at times. Even smart pilots run out of gas and it's one of the most common causes of accidents.

    Many many different things can lead to that. Perhaps you're borrowing a car and are not familiar with the various guages and such. Perhaps it's a rural area where there are no open stations at night and you've got little choice but to try to get home. Perhaps when you filled you only had a couple dollars--in the Prius it takes a minimum of 3-4 gallons of fuel to reset the guage, otherwise the pip keeps flashing.

    I think this thread is of value for a number of reasons.
    1) We now are all more aware of exactly what the behavior of the vehicle is/will be if we should run out of gas and that it is different from both previous editions of the Prius. Maybe this isn't important if it's your first Prius as you never knew differently, but to those of us who like to push for maximum tank distance it's very important so we don't end up dead in the road.

    2) It opens the discussion as to "Why" did Toyota choose to change the behavior. As mentioned previously it may be to prevent severe battery discharge and damage, but that arguement seems inadequate as they could easily build in a threshold for SOC to do the same thing while allowing a "Limp" mode. I now wonder if there is ANY Limp mode in the Prius III when there are other problems/issues. I personally was thrilled to have the Limp mode in my Prius II when I suffered a software issue that shut down the ICE while I was at an intersection and needed to get out of the way to allow traffic to flow while I had my 3 kids in the car with me.

    While newbies here might not appreciate it yet, many of us do "experiments" on our Prius to test it's limits, abilities and to learn more about how it works and its behavior under various conditions. We'd never know as much about the Prius II without folks willing to do these things. Insulting the OP b/c he did this is inappropriate. While it may be something you would not choose to do he is making a contribution to our knowledge base of the Prius III. Had he not done this we would first learn of this situation when some newbie posted up a horror story about being in 5pm traffic when it happened and how they were traumatized to the point that they no longer trust the car.
     
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  10. patsparks

    patsparks An Aussie perspective

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    What I am saying is the prius has built in features that allow it to run on battery only under certain circumstances. When you have no hydrocarbon fuel in the tank to allow the ICE to run on demand you may be forcing the electric power train to operate outside its designed operational parameters as determined by Prius engineers. When there is hydrocarbon fuel in the tank the ECU will engage the ICE if it is needed to power the car and prevent harm to the traction battery pack you may even do harm even if the battery is within its normal range of state of charge by causing the battery to discharge at a rate which may be harmful to the battery pack. And, even though it is argued here that being able to drive the Prius after it runs out of hydrocarbon fuel may allow a person to get out of a dangerous situation, it may conversely allow a person to place themselves in a perilous situation. To prevent this Toyota have chosen to make the new Prius behave like a conventional car when it runs out of hydrocarbon fuel, it stops being propelled.
     
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  11. efusco

    efusco Moderator Emeritus
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    Indeed that may be the reason it operates this way, but that's yet to be determined and i'd like to know what would lead them to change this from the previous 10 years of Prii that had a well controlled and usable "limp home mode". Speed and battery SOC were limited specifically to prevent damage to the battery.

    And you still haven't addressed the issue of SOC Pat. If the battery is within it's safe SOC and the car automatically shuts off when it reaches an unsafe SOC what's the harm?

    I'm not one claiming that this is a safety issue or anything like that, but I'm baffled by why they would implement this change and while lots of people feel like bashing the OP or anyone who chooses to defend him, I'm yet to see even one logical post that would explain how maintaining the feature, with SOC and max speed limits, would be dangerous or disadvantageous.
     
  12. Zythryn

    Zythryn Senior Member

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    Bob, I very much appreciate your technical aptitude, research and almost always your rational posts.
    In this case though, you seem to equate running out of gas with the same danger as being in an accident without a seatbelt.

    Running out of gas is something under the drivers own control except in case of equipment failure, and even then, if the gas gauge failure is known, it is still somewhat under the driver's control.
    Accidents are not (otherwise they would be called 'purposefuls';)).

    The story you posted is a great example, if the truck driver had run out of gas a mile back the pileup would have been avoided.
    No mention in there of the first accident being caused by someone running out of gas and the second definately was not.

    People need to be responsible when operating a motor vehicle. When they are not, accidents happen. The vehicle should give the driver the tools to gather the information they need in order to be careful and responsible.
    By shifting into neutral, the Prius acts like any other car, you can move over to the shoulder as you drift to a stop.

    I would agree, due to the engine on/engine off of the Prius, that there should be a warning light/sound when you have actually run out so you know to pull over to the shoulder (for all I know there is?).

    I would also argue that of the thousands of people that do pull over to the shoulder every day for any mechanical issue, most don't cause or end up in an accident.
    I would be willing to bet that far more accidents are caused by people speeding than are caused by people who are pulled over on a shoulder.
     
  13. efusco

    efusco Moderator Emeritus
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    Let me say that I agree that Bob's hyperbole about the "deadly danger" the lack of being able to use the battery in an out of gas condition is counter productive and distracts from our ability rationally discuss the "why's" how Toyota came to produce the Prius III this way. And it's a little disappointing b/c Bob's pet project--the "Bell the Hybrids" bill his opponents use similar hyperbole without supporting data to frighten people into supporting the bill.

    Perhaps we just need a new thread in the technical forum to discuss the facts of why the 'limp home' mode was disabled in the new Prius so we can remove the emotion and hyperbole and maybe get something productive out of it.
     
  14. Zythryn

    Zythryn Senior Member

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    To me, simply as a guess, I see two likely possibilities:
    1. Too many customer complaints or even lawsuits over damage to the battery after running out of gas ('the car let me drive it shouldn't have caused that damage to itself judge!').
    2. Too many warranty repairs on systems mistreated in that way.
    3. (ok, I thought of another) If it was found that operating the vehicle in a hamstrung manner (low power or such) was more likely to cause accidents either under operation or when the battery finally gave out.
     
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  15. CAR4TWO

    CAR4TWO New Member

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    What's the big deal if you can only limp for up to one mile on EV? No car can limp anywhere when you run out of gas. Is that true or not? If people can't figure out when it is time to gas-up, they should not be driving a car. Lastly, keeping gas in a car is a pretty simple task hardly worth all the hub-ub here on the forum. It is kind of fun watching everyone make a big deal about nothing. We should all be carrying a sign in our Prius that we could hold up that says, "NEED GAS." Can you imagine a Prius owner holding up a sign that says need gas?
     
  16. efusco

    efusco Moderator Emeritus
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    While I don't agree with that self-rightous opinion, let's assume it's OK, that people shouldn't be driving a car if they might run out of gas.

    What about the ICE stalling for other reasons? Bad gas, failed fuel pump, overheating, ECU caused condition (as occured in the early '04 Prius), failed fuel injector, bad MAF sensor, electronic ignition failure...probably a dozen or more other reasons all outside of the driver's direct control or ability to predict or prevent.

    In those conditions the ability to limp along to a safe, out of traffic spot would be very helpful to both the driver and to other people on the road would it not?

    So even all the apparently superior humans on this forum who could never make a mistake and would never find themselves in an emergency situation and run out of gas 'might' have an ICE failure for other reasons.

    Is it possible we move this discussion from the simple minded "just don't run out of gas, stupid" attitude to one of the technical issues and potentially even 'fixes' or solutions?
     
  17. CAR4TWO

    CAR4TWO New Member

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    Doc that is why we drive a Toyota or Honda so we won't be found disabled along side the road. Mechanical failure, while it still happens, is exceeding rare.
     
  18. fred garvin

    fred garvin New Member

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    I don't interpret "reasoably possible" to include getting into a car that has a hole in the fuel tank so i run out. That is a very low percentage possibility which i put in the not reasonably possible bin.

    i am going to stop arguing about the words "reasonably possible".

    can i say with 1000% certainty i will never run out? Of course not. You could track me down and empty my tank to just to prove your point.

    a hunter could mistake my car for a moose and shoot a hole in the tank.

    etc

    but i won't be running out of gas cause i won't take any risks with it
     
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  19. CAR4TWO

    CAR4TWO New Member

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    This fix would be Roadside Service. Own a Mercedes? Call 1-800-for Mercedes and they will come and fix your car. Every 100,000 miles we have a flat tire so again, fix it or call for Roadside Service. With a cell phone, you can call for help. I carry a can of Fix-A-Flat, plugs and patches including a tire pump that runs off the car's battery. In the Corvette, I have run flat tires so I don't need to fix anything. The worst car made today is better than the best car made 10 years ago. You can travel down the road with confidence even in a Chrysler.
     
  20. efusco

    efusco Moderator Emeritus
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    A bit dismissive of the issue at hand isn't it?
     
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