The Prius Bladder/Guess Gauge... For Dummies! (with easy-to-understand-illustration)

I kinda like how you interpret that! There's what, a tablespoon of petrol left when the last pip flashes?

 

no kidding

we can go a little over 400ft on a tablespoon of fuel, so when that thing starts blinking you better be close

 

I stare down the flashing pip with impunity! A, relatively, close quantification is all I need

 

Okay, that's just weird.
.
_H*

 

Excellente!

 

well if this was posted in honor of my & all of the other dufuses that have run out of gas, I appreciate it.
I'm a pretty mechanical person having grown-up in the Used car wholesale business, and I'm still trying to understand why Toyota would want such important info kept secret. Just say its a a bladder in the damn manuel, what's so hard about that?

 

I thought it was inaccurate the other way - mine started flashing and I stopped (20 miles later) and there were still 3 gallons left.

 

So I'm sitting in a local restaurant telling my wife in great detail about the bladder and volume differences, when I realize the couple at the table next to us are looking at me with disgust....

Sorry not my bladder...my car's.

 

Talking about running low on gas -- can the Prius still be driven on the electric motor and how long?

 

Okay (deep breath), here we go again: Why do you think you had three gallons left? How would you know you had three gallons left? The answer to these questions is that you didn't know and there is no way for you to know. It's not you personally, no one can tell. The fuel bladder causes the tank to have a variable volume, so there is no way to calculate how much fuel is in the tank. This is because you don't know how much was there at the start.

The bottom end of the tank works pretty much like any fuel tank: When you get to the bottom there is a small amount of unusable fuel. This is true with or without a bladder. The full condition is where the bladder adds uncertainty. Depending on how stretchy it feels on a given day, and how touchy the gas pump, the tank will stop filling at an effectively random spot on any given day. The odds are good that it will be somewhere between 10 and 11 gallons of usable fuel, but you don't have any guarantee.

Tom

 

But how do you know how much you have left?

I have done as much as 30 miles after flashing in my '02, but I could never put more than 9 gallons in. The explanation given here is that the gas "bladder" in fact holds somewhat less than the stated 11 gallons capacity.

The key thing is you can never put exactly the same amount when you fill-up - the bladder is sometimes stiffer, sometimes softer apparently due to temperature and who knows what so the amount at fill-up varies tank to tank even if you fill at the same moment every time after you see the flash come.

On my car also it is usually the case that if I come home with 2 solid bars, I often find the car with a single solid bar in the morning. Obviously, no gas was consumed overnight, but the reported level is different. So the gas gauge is not at all accurate.

 

I doubt it.

I suspect that you are either guessing (and guessing wrong) or you measured incorrectly.

 

Simple math - the tank holds 11.9 gallons. I put 8.xxx gallons in it, thus the three gallons.

And the car was full - first tank, I watched him (salesdork) fill it.

 

Just under a gallon, in about 60% of the cases. Your results may vary.

 

Prusuming we filled up all the way, are we?

 

You guys are pretty adversarial, eh?

 

Yes.

In the majority of cases, long enough to get you safely to the side of the road and out of the lanes of traffic.

Keep in mind that it is recommended that you avoid this situation in the first place. Running out of gas can endanger you and others driving on the road.

There is no way of knowing exactly how far you'll get without gas. It depends on many variables. How charged up is the battery? How fast are you driving? What is the profile of the distance you'll be driving? How windy is it? What direction is the wind coming from in relation to the vehicle heading throughout the distance? Is there anything on the road (salt, snow, sand, water, etc)? How much precipitation is there? How much air is in your tires? How much do the cargo and passengers weigh?

I'm sure there is more, but that's all I can think of at the moment.

Advice #1 "Fill the tank before the last pip starts to flash."

Advice #2 "If you ignore Advice #1, then immediately fill the tank at the closest available location after the last pip starts to flash.
"
Advice #3 "If you ignore Advice #1, and #2, then don't run out of gas."

Advice #4 "If you ignore Advice #1, #2, and #3, then use the electric motor to get the car safely out of traffic and then stop."

Advice #5 "If you ignore Advice #1, #2, #3, and #4, then stop before you have run the battery so far down that the car shuts off."

Advice #6 "If you ignore Advice #1, #2, #3, #4, and #5, then do not turn the car back on after it shuts off."

Advice #7 "If you ignore Advice #1, #2, #3, #4, #5, and #6, then you are beyond help. Your battery may be ok, it may be damaged right away, or it may seem fine, but have a shortened lifespan. If the battery ever does develop a problem after this, it would seem rather silly to expect any warranty to pay for any repair costs incurred."

 

Short answer: no, and just pull over.

Long answer: yes, and until you destroy the hybrid battery. You might do a search on this site concerning running out of gas.