[WARNING] Running out of gas (Gen III)

Your chance of having a flat tire is once in every 100,000 miles. I can not believe this discussion. My rule is that I will go down to an 1/8th of a tank. After that, I'm looking for fuel. In the airplane, I will not let it go below 1 hour left in the tanks. I have to find an airport in the next 120 miles. Seriously, I want gas before I start to use that last hour in the airplane. Letting your car run out of fuel is flat out the dumbest thing anyone can do.

What do you call those bars? Pips? The Prius tells you how many miles you have left in the tank. At 50 miles, I would be looking for a gas station. Knowing me, I would be looking with 75 miles showing. Every good driver should know when it is time to top off the tank. It is flat out irresponsible to run out of gas.

There is a lot of common sense on this BB. I especially liked, "Keep the gas tank full, problem solved." All cars can run out of gas and they all come to a complete stop when they do. It sounds like I am speaking to a group of new drivers. I'm actually laughing as I write this. You are taking all this to seriously. By the way, if the gas gage starts to flash, fill it up. How hard is that?

Thanks for the laughs! I was wondering why so many were posting to this thread. Well, now I know.

 

So, who killed who? Was it the car's fault for not providing more than 2 warnings or was it the drivers' fault for ignoring the warnings and not filling up the tank prior to getting on the highway?

Thanks for justifying your lack of judgement. Stop blaming technology and sack up. You are a bad driver for risking other people's lives. As you stated, this is a serious situation when a car runs out of gas (SEE ABOVE PICTURE). YOU are contributing to the next death.

 

I work as an engineer and I am always designing for rare events. The problem with your detractors is that with any rarely occurring event, time is the great equalizer. If given enough time, the likelihood of something rare occurring approaches a certainty.

The really curious part of all of this is the actual lockout itself. Why design such a lockout in the first place? A few people are speculating that it is for increased traction battery life. I cannot see how this speculation is true since Toyota engineers provide a way for people to directly use the traction battery (ie EV mode). If battery life was such a serious concern why allow a customer to put such an extra strain on a battery? Batteries normally have a limited charge/discharge cycle life. EV mode seems like a much more efficient way to destroy a battery than allowing a driver to use the remaining charge during "out of gas" situations. Since the EV mode button made it to the production model, I can infer that Toyota engineers were confident that regular usage of the EV button wouldn't impose a financial burden on Toyota's battery warranty program.

I think it is much more likely that this was a simple oversight by the person programming the main system and not an on-purpose change in the product.


Many of your detractors are saying "Well don't run out of gas". While this was the particular way you tested the emergency functions of your Prius, it is not the only possible way to get into an emergency situation. There are probably hundreds of ways a person can find themselves in a vehicle without ICE power. A clogged fuel filter or broken fuel pump come immediately to mind.


I am not a lawyer but I sense a good case against them for this particular design limitation/oversight. Their disregard for human safety may hold up in court given the fact that they included an EV button and they had previously allowed for emergency maneuvers in a prior design.

 

was the pillow comfy at the Holiday Inn Express last night?

 

I am also an Engineer with 32 years experience. I've never had the luxury of designing for events that a) occur 0.1% of the time or less after ignoring all sorts of other earlier warnings (miles to empty, fuel guage, warning light) and b) the severity of the failure is minimal (you pull over stranded, not the end of the world). I can think of a lot of potential features with higher probability of providing a benefit. A good Engineer would factor in probability and severity, I'd be willing to bet the Engineers at Toyota do. For landing planes, defects need to be zero because of the severity. For a car running out of gas with all the early warning already provided, the probability is low and the severity is almost nil. The wreck pic is clearly grasping at straws.

And as another poster said, Toyota might not want drivers to think 'running out of gas is no big deal because I can drive on battery to the next gas station.'

 

I'm not sure I agree with a 0.1% occurrence rate. Most vehicles have at least one failure or breakdown in their lifespan.

The risk to a driver is dependant on the situation. You cannot assume that a driver will be able to pull over during a failure. I can envision the rate of ICE failures is more likely to happen during start/stop cycles than while at speed. An ICE failure while in the middle of stop-and-go traffic could be a serious issue - even life threatening. How about an ICE failure while crossing railroad tracks? Or while on top of railroad tracks while waiting at a red light? (Yes, I know you are not supposed to do that. It does not change the fact that it happens.)

Automobile manufacturers have always had to contend with out of the ordinary situations. I still think this was a programmer’s oversight and not a deliberate action by Toyota; however, that does not change the fact that I would rather have this missing feature. The question I really want answered is, "How do we get it back?"

 

Or Toyota could put in a nifty display on the dash next to the speedometer; let's call it a 'gas gauge' that flashes on the last pip for over 100 miles of driving (about two to three hours of continuous driving in most cases)...

Oh, my mistake, they already do... must be a new gizmo for the 2010 cars... imagine that, a device that warns you 100 miles and more in advance to pull over and get fuel... Pure genius...

Rick
#4 2006

 

I am not a lawyer either, but I agree with this statement.

It supports my previous remark on this thread that inclusion of the EV button in the G3 Prius is a bad idea, since it does foster a mindset that the car can operate in all-electric mode on any occasion. It can, provided there is gas available to run the ICE when the HV battery gets down to 40% SOC.
What Toyota have tried to prevent is unlimited use of the HV battery as the primary driver in an open-ended situation, when the ICE is not available.

 

Toyota does not advertise this as an electric car. They have warnings in the (680+ pages) operators manual telling you NOT to run the tank empty. Now that Bob's told us, no one on PC should expect their car to move on empty (so no PC'ers have a legitimate lawsuit). No other car allows you to run on empty. The Prius if you follow the "rules" is no more unsafe than any other car that stops of the roadway for what ever reason.

With all that said though, as Bob mentioned, it's probably a fix Toyota could have done, not sure why and they have not told us, but it is what it is.

We all now know NOT to run out of gas regardless of what your GenII Prius was capable of.

Judging from Bob's threads I've seen that he does a very complete assessment when he runs his experiments and I am to guess a venture that he does nothing dangerous for the purpose of providing us non-technical advice based on a lot of technical data and analysis. Personally, I like knowing how far my car will go on empty. In 2007 when I got my TCH a couple of people did uncontrolled run-outs to test it. I never really trusted data from these guys. I know though that when Bob did it he set it up and monitored the gage settings as he was testing the limits.

Is he a kook? Possibly as many of us are. Most Engineers (I R 1) are generally considered such from all but the Engineering community (that group being those that would not be provided any of todays modern technologies without us)

It's just a shame Toyota does not provide this data to us. (Not that it would keep Bob from double checking them )

 

For the NAV systems, it should have the voice come on and say "It's Empty, No, really it's empty. Prepare to STOP. NOW". She may want to scream it so that people won't confuse it with her normally pleasant voice.

I gues with the new invention "gas guage" there could be a flashing red light that says EMPTY over the entire display panel

 

Have you stopped to check each disabled vehicle along the side of the road, to make sure that it's disability isn't a lack of fuel?

I still see numerous disabled vehicles out there.

 

No other car allows you to run on empty? Since when? I thought we've been comparing this very functionality to that of the GenII Prius.

Even if they required your signature on a release form during sale of the vehicle, it would not negate their willing neglect for operator safety. So I wouldn't go so far as to say "no PC'ers have a legitimate lawsuit". But of course, this all depends on the State you live in and real advice from a real lawyer - which I have already noted that I am not.

None of it changes the fact that I would like to be able to use EV mode when the ICE has problems (out of gas being only one error state). The battery might only have enough charge to get me 100feet but I would like to have that option.

 

See post #91. If you don't agree with it, show us your numbers instead of "I'm not sure I agree with..." and then nothing. 0.1% would be about 18 occurrences BTW...

 

The above takes the cake for being the most ridiculously contrived attempt to remove your foot from your own mouth. It was a dumb thing to claim, and you only continue to make it worse, even after you said (falsely) that you were going to drop it.

You might as well twist it to say 99.9% of us will never have an accident...because few of us have one on any given day. Yes, I'm sure that we all would have known what you meant if you worded it: "Like 99.9% of the population, I will never have a car accident." Then try to convince us that you meant something else by looking at it on a daily basis instead.

Let's look at what you actually said, versus what you are claiming now.

Pretty much shows all the above claims you make to be at odds with what you really said. Nice try at spin, but once one examines the record it becomes clear that you are now trying to deceive the readers. You tried to make it sound like running out of gas was almost impossible to do other than intentional.

But the one small survey I found had an even mix between those who had and had not run out of gas. But even if that is correct it is going to undercount. Why? Because few of them are likely to have stopped driving. How many of the fraction who said "no" will never run out of gas? I have no idea other than it is unlikely to be zero, and it is definitely not going to be a negative number...

You and your ilk fail to distinguish between the possibility of carelessly running out of gas (through actual negligence), taking a calculated risk (as in pushing it to lower levels on the gauge), or other circumstances beyond the driver's actual control.

Your claim is about as reasonable as saying you will never have an accident because you don't take chances...or never make a mistake.

 

All this, and yet still no answer to (surely your answer isn't 50-50)...

 

Hummm, seems like more time is spent on these technical topics defending positions than on the topic. With all the nitpicking over language these really comments should be processed throughour lawyer before posting.

 

To my knowledge, none of the vehicles in this crash was out of fuel. Please try to differentiate crashes and fuel starve. With the bladder being gone, there is no reason to run out of fuel, and no reason it should stress the battery when one has ignored 120+ miles of warnings. I appreciate knowing about this change, but it does not bother me.