[WARNING] Running out of gas (Gen III)

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

  1. bwilson4web

    bwilson4web i3 and Prime

    Joined:
    Nov 25, 2005
    22,890
    12,779
    0
    Location:
    Huntsville AL with 2014 BMW i3-REx
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Plus
    Take the human out of the equation:
    • $2,400 - battery replacement cost
    • $24,000 - Prius with battery replacement cost
    The change means the $2,400 battery can not be 'sacrificed' to save the $24,000 car.

    Bob Wilson
     
  2. patsparks

    patsparks An Aussie perspective

    Joined:
    Jul 12, 2007
    10,664
    562
    0
    Location:
    Adelaide South Australia
    Vehicle:
    2004 Prius
    Model:
    N/A
    Sorry Bob, I still don't get the "I must run my tank dry" brigade.
    I know you're are doing research but I still don't get it.
     
    4 people like this.
  3. Celtic Blue

    Celtic Blue New Member

    Joined:
    Aug 4, 2008
    2,224
    139
    0
    Location:
    Midwest
    Vehicle:
    2008 Prius
    Actually, it is quite easy to see that limp mode need not be a major problem. The GenII could handle it, the GenIII could as well as it is not a major departure in the drivetrain or battery. The reported behaviour looks much more like a heavy handed, CYA, foolish approach than something that required the input of a few working neurons.

    They already did a "complete rewrite of the software" else it would behave more like the GenII. ;) Maybe they shouldn't have spent so much effort on changing it and thereby degrading it? :D

    If they are worried about heavy amp draws they could limit that (afterall they already program the accelerator pedal response to account for that in normal driving.) This doesn't look smart, it looks really dumb. Can't imagine why anyone would leap to its defense other than being nervous nellies.
     
  4. LRKingII

    LRKingII New Member

    Joined:
    May 31, 2009
    679
    131
    0
    Location:
    Idaho
    Vehicle:
    2010 Prius
    Model:
    III
    I guess i just dont understand running out of gas. Been driving since 1955 and have NEVER ran out of gas...in my car. :D
     
    2 people like this.
  5. Midpack

    Midpack Member

    Joined:
    Apr 25, 2009
    461
    42
    0
    Location:
    Chicagoland
    Vehicle:
    2012 Prius
    Model:
    Three
    Mildly interesting, but looks like creating a problem where none exists. As many have said, no different than every ICE car ever made. What's next, bashing the car into a tree to see if the airbags work as expected :eek: ? [Exaggerating to make a point if you're too literal minded to get it].

    Like 99.9% of the population, I will never run a car out of gas, never have in 38 years of driving and can guarantee I never will. So I want Toyota to protect the traction battery, I can afford $2,400 but I don't want to. Good grief...
     
    1 person likes this.
  6. Mike Dimmick

    Mike Dimmick Active Member

    Joined:
    Aug 8, 2008
    963
    244
    0
    Location:
    Reading, UK
    Vehicle:
    Other Hybrid
    Model:
    N/A
    The 2G only allows you to draw down to two bars in EV mode. After that point it starts the engine. An engine start does need a reasonable amount of energy to turn the engine over, start the various pumps and apply spark.

    The impression I get is that when the 2G was out of fuel, it would let you drain the battery right down to dead - not that I have ever tried this. If the 3G doesn't let you do this, it's just greater consistency. As far as the car is concerned, less than two bars is too little to drive on. Better to preserve enough charge that the engine can be restarted after fuel is added, than to leave it requiring towing - or a battery replacement.

    The concept that you should be able to drive this car without fuel is absurd. It's a charge-sustaining hybrid, a gas car. It's not an EV.
     
    5 people like this.
  7. XMAN LIVE

    XMAN LIVE "Just have Fun!"

    Joined:
    May 21, 2009
    271
    23
    49
    Location:
    Cypress TX
    Vehicle:
    2010 Prius
    Model:
    V
    I side with Bob on this one. You never know when you may need to be able to use the old battery way of getting off the road. I agree I like having a seatbelt. I haven't had to use it in like 15 years, so I really don't understand why I want one. Give it a break auto switching to battery when running out of gas was a working feature in the past and it made thing fun. With this bit of extra battery, I was able to try to set new mpg per tank goals all the time. It was like a using a free, get out of jail card. It was a feature that gave you a boost of confidence that made you feel safe when running out of gas. I only ran out of gas twice in my GII. It smells better than caring and extra gallon of gas around. I will admit even in my GII, I have learned my lesson and will not be trying to set records so far from home or at night. Give Bob a break he has done a good thing to point out that GIII does not perform in the same way as GII. Now what we really need is for someone else to report their out of gas story, to make sure Bob’s car is not broken and performing incorrectly. I have a hard time understanding why this feature is removed. Now that we have a legal EV button this makes no since to me.
    :rockon::D:rockon::D:rockon::D:rockon::D:rockon::D:rockon::D:rockon::D:rockon::D:rockon::D:mod:
     
  8. LoveMyPriusIII

    LoveMyPriusIII New Member

    Joined:
    Jun 14, 2009
    66
    5
    0
    Location:
    Florida
    Vehicle:
    2010 Prius
    Model:
    III
    My take on this is simple. If I were to run out of gas I would expect electric power to take over until the battery is at the preset point where any other discharge would shorten the life of the battery. Bob, did you perform this test when there was 5 or more bars of battery life shown? I want to know if it shut down the system even with a "fully" charged battery. If it does then I agree this is a problem.

    If it just shuts it down when the battery hits that predefined point than I agree with Toyota to shut down the system just like a regular car. They don't want to shell out the cost for a new battery within the warranty because a user keeps running out of gas and fully discharges the battery over and over.
     
  9. bwilson4web

    bwilson4web i3 and Prime

    Joined:
    Nov 25, 2005
    22,890
    12,779
    0
    Location:
    Huntsville AL with 2014 BMW i3-REx
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Plus
    I'm already working on the experiment design. It would be a lot easier if I can figure out how to 'spoof' the system into thinking the engine is out of fuel. Then I could replicate the problem without the excitement of a field test.

    Bob Wilson
     
  10. Spartane

    Spartane Member

    Joined:
    Jun 4, 2009
    149
    42
    0
    Location:
    Mississauga, Canada
    Vehicle:
    2010 Prius
    Model:
    III
    As we move forward in time, technology improves. The Toyota Prius is a wonderful example of this (and hence the name "Prius"). The previous version of the car had a technology gain that allowed one to drive even after the engine ran out of gas. It became a well known feature that people would often talk about.

    The newer version has eliminated that gain. In my view, this is a technological step backwards rather than forward, and one that does not well suit the Prius name. In addition, it could compromise someone's safety if it happens under bad conditions.

    Two main arguments are presented to support this regression:

    1. Existing gas cars don't run without fuel so the Prius shouldn't either. This argument suggests that it's OK for technology to move backwards as long as it matches the mainstream.

    2. I've never run out of fuel in my XX number of years driving so nobody else should either. Imagine someone's son or daughter driving the Prius late some evening with a few friends in the car. When their friends ask why they're driving the car with the fuel guage on empty, they respond "This car goes forever on a tank of gas and dad will fill it up tomorrow. And even if it does run out, it's a hybrid and I can still drive it for a few miles on the battery". Younger people have limited funds and their judgment is frequently optimistic and not as well developed as it might be when they're older.
     
    2 people like this.
  11. XMAN LIVE

    XMAN LIVE "Just have Fun!"

    Joined:
    May 21, 2009
    271
    23
    49
    Location:
    Cypress TX
    Vehicle:
    2010 Prius
    Model:
    V
    On GII you could bring battery meter down to 0 bars. Both time for me I had 5 bars when runing out of gas. In Bob's pick he has 2 bars on battery, On GII two bars, was low and ICE would come on for sure, if you had gas. LOL
     
  12. Celtic Blue

    Celtic Blue New Member

    Joined:
    Aug 4, 2008
    2,224
    139
    0
    Location:
    Midwest
    Vehicle:
    2008 Prius
    There is a hole in that big enough to drive a Hummer through...since they put an EV mode into non-US variants.

    Others have hit the nail on the head, the behaviour that Toyota has programmed in for apparent out of gas situations is a regressive, capability limiting one. It's cutting off the nose to spite the face.

    A smart engineer could both protect the battery and allow use of the remaining charge. Toyota has some serious weaknesses in the interface anyway (lack of any coolant temps being an obvious one, fuel gauge another.) Treating the driver like a mushroom is not helpful (keep 'em in the dark and feed 'em s***.) One would hope that Toyota would attempt to move forward the feedback system as well as various non-standard operating responses, not backward.

    What's next? Automatic shut off the car on the blinking pip? Refusal to move until the battery is optimally charged and temperature adjusted?

    Here you have a car that should have an ADVANTAGE in such situations and instead they've intentionally handicapped it. That is dumb, dumb, dumb. Way to go, give your critics ammunition when instead you could be whacking competitors over the head and shoulders with an advantage.

    And dumber since they've included a weak digital fuel gauge that is much less functional than a traditional analog gauge. It essentially goes blind at 1/8th tank. The result is a substantial and wholly unnecessary loss in effective range. Essentially the Prius is carrying around about 1.5 to 2 gallons of extra fuel and associated tank weight and lost interior space for no improvement in effective range.
     
  13. Celtic Blue

    Celtic Blue New Member

    Joined:
    Aug 4, 2008
    2,224
    139
    0
    Location:
    Midwest
    Vehicle:
    2008 Prius
    You just refuted your argument. If you "will never run a car out of gas" then you don't need Toyota to protect your traction battery in the way described. :D

    I would love to know where you get your statistics from as I'm at least 200% certain they are bogus (give or take 100%.) :p I've seen and known too many people who have run out of gas for that to be correct. If I was going to pick a number out of the air I would be inclined to select 50%. Actually, I just looked up a survey (not scientific and fairly small sample); it was evenly split yes and no.

    I've never run a vehicle with a working fuel sender out of gas, but I've run out of gas before, twice due to broken senders in others cars, one compounded by a leaking tank. Yet, for the past 20 years at least I've taken the vast majority of my own vehicles' tanks under the "empty" mark (which is actually about 1/8th tank indicated) without running any of them out of gas, ever. I don't expect to run out of gas unless a sender goes bad or some other failure occurs.
     
  14. Tech_Guy

    Tech_Guy Class Clown

    Joined:
    Jan 8, 2007
    868
    119
    0
    Location:
    Silicon Valley, CA --- Land of Fruits & Nuts
    Vehicle:
    2011 Prius
    Model:
    Two
    The Prius certainly is a different animal compared to most cars. As I recall there is no true N (neutral) to shift into because there is no clutch and no N position in the Prius "transmission". The wheels are always connected to the planetary power split device; and MG1, MG2, and the ICE are always connected. Am I wrong?

    Keith
     
  15. timberwolf

    timberwolf New Member

    Joined:
    Oct 26, 2008
    220
    31
    0
    Location:
    UK
    Vehicle:
    2008 Prius
    In some places you can get fined for running out of gas.
     
  16. Celtic Blue

    Celtic Blue New Member

    Joined:
    Aug 4, 2008
    2,224
    139
    0
    Location:
    Midwest
    Vehicle:
    2008 Prius
    In some places it is illegal to use a cell phone while in a car. So let's eliminate the bluetooth option. And there are some places where you are not allowed to back up, so let's get rid of reverse while we are at it.

    So do they automatically fine EV drivers if they enter these areas? They are out of gas, unless they put a container of gas in the back.

    Now if one has hybrid that can run a short distance on battery that person is really not out of gas until the usable charge is depleted...because that battery energy came from gasoline. You see, what matters is whether or not they are immobile. And by the logic you are employing, Toyota is making it more likely that the average driver will end up immobile in one of these areas. But that's a good thing, right?
     
  17. LRKingII

    LRKingII New Member

    Joined:
    May 31, 2009
    679
    131
    0
    Location:
    Idaho
    Vehicle:
    2010 Prius
    Model:
    III
    Care to tell me where it's illegal to use a cell phone or use reverse?

    The average driver is smart enough to not run out of gas.
     
  18. Joe G

    Joe G Junior Member

    Joined:
    Jun 27, 2009
    2
    0
    0
    Location:
    Plainsboro, NJ
    Vehicle:
    2012 Prius c
    Model:
    III
    I too have run out of gas, and while I don't remember my indicator status other than a big exclamation mark when I actually ran out. I can tell you that I was WELL aware I was about to run out, as the fuel indicator has been blinking and I was already in the right hand lane in heavy traffic, and ready to pull over to the side.

    I know I heard it, but you may wish to consider talking to your mechanic/dealer about making the audible low-gas alarm louder for when you drop below 1 gallon of fuel left in the tank.

    And while I didn't loose all ability to drive, but I could only move along at 3-5MPH in "B" mode, not "D" mode (that won't work - for obvious reasons), when you are out of gas. I happened to cruise right up to a gas-pump.

    All in all - quite embarrassing, as I'm sure you'd agree, nothing says irony quite like having your hybrid run out of gas.

    Speaking from my limited experience, I wouldn't recommend driving more than about 500-1000 yards before you should not drive it at all, I view it not as 4wheeled miracle-machine, just a car with a big-a** battery. And being as large and probably expensive as that is - I'm respectful not to run out of gas on a regular basis.

    Otherwise I see no particular reason that running out of gas with a Prius or other hybrid is any more or less dangerous than with another light-duty car, and just in case, I have a small gas container in case I have to hoof it over to the nearest gas-station.
     
  19. Randall Rash

    Randall Rash Member

    Joined:
    Sep 13, 2006
    149
    25
    0
    Location:
    Rockwall, TX
    Vehicle:
    2010 Prius
    Model:
    IV
    Even for the very cautious, unless you fill up on each trip out the door, you are relying on the fuel guage or even if relying on miles driven, you may not realize you have a fuel leak. Since we can put a man on the moon (and we know that Neil Armstrong and crew had 60 seconds of fuel left), we should just know within an ounce, how much fuel is left. But I don't knock Toyota because I have not seen that accuracy in any car. And since I'm not in the business, I just assume there is a good reason. (Such as the cost to deliver that accuracy). I just fill up when I get low, or get knots in my stomach when getting caught driving in remote areas less than low.:eek:
     
  20. Celtic Blue

    Celtic Blue New Member

    Joined:
    Aug 4, 2008
    2,224
    139
    0
    Location:
    Midwest
    Vehicle:
    2008 Prius
    For cell phones, see the following extensive list: State Cell Phone Driving Laws
    It is actually handheld cell use. (However, the real danger is talking on the phone itself while driving--equivalent to DWI. It's hard to pick out the DWI's anymore in a traffic stream as the suspected "drunk" is almost always on a cell phone.) Handsfree cell phone use is only forbidden for certain age groups and drivers (such as bus drivers). And some companies/govts. actually require drivers to park their cars to talk on the phone.

    As for backing, it is illegal to back into parking spaces in quite a few places. I also remember it being forbidden to use reverse at the gas station on the military base I worked at. Going in reverse down a one way street is also illegal as I understand it.

    The point of course is how silly it was for the other poster to use the example provided as if it was some sort of proof.

    Taking this to a bit more of an extreme to make the point, there are places where one is forbidden to turn right, left, or either; but that doesn't mean that the steering wheel should be disabled.

    Apparently not, because as best I can tell half of the average drivers have run out of gas (not the 0.1% claimed.)

    Being "smart" doesn't help when the gauge fails or is improperly calibrated. Ask the folks who have gone empty at 2 pips. The GenII gas tank (bladder and gauge) was seemingly designed to make it more likely the average driver would run out of gas, not less.
     
Loading...