Fuel Gauge

Hi Harper - well said.
As we learn more about the car, information changes and gets updated - going back to previous posts does help but recent experiences tend to be more accurate.
Its evolution - so ask away !
Pinball

 

The fuel gauge is my biggest gripe about the car. I dont trust the average and fill up when I'm on my last bar. To experiement, I filled my tank to shut off and squeezed in an extra 3/4 gallons. Total miles on that tank was 434, the pump shut at 8.2 and I filled up close to 9 gallons.

That tank, I was averaging 49.4 mpg and had gone 245 miles before the last bar started to blink. I filled up the car with gas until shut off and squeezed in 1/2 gallon. Guess how many gallons? 5.2 :huh: :huh: :huh: That makes sense to me, but why the gauge is blinking and the screen is showing "Add Fuel" is beyond me.

I understand the whole bladder thing and I read many posts about this topic, but I only wish the gauge was a little more consistent. Sometimes I can go 500 miles before the light blinks, sometimes I can go 400, and other times, I might get 250 miles.

BTW, is a 2005 that I bought new in March and have over 21,000 miles on it.

 

I understand the need to have people search the forums for questions that have already been discussed. But seriously, what the hell are we going to talk about here if we don't talk about fuel economy and some of the other core Prius issues? Using this logic, eventually Prius Chat will be completely worthless. Everything will have been "discussed already." So folks will be left with posting about absurd OCD driven observations like the color of the cigarette lighter cap in the new 2006 edition, or meaningless banter like "Who has neighbors who you think envy your Prius, but drive SUVs due to self esteem issues?" I mean, c'mon... lets lighten up a bit and realize that flaming people in these forums is really a ridiculous and cowardly thing to do. It's the internet version of road rage, only instead of being safe from reprisal for your bad behavior because your safe in your car, your safe behind a computer monitor at an unknow location. In general though, you should treat people like you would if they were standing in front of you... this is also known as 'respect.'

-mcslain

 

There are plenty of things to chat about. I saw the post and was just tired of people trying to push the tank to the limits, when there is no need. Many people try to push it so far, that the run out of gas, when there is absolutely no need.

I don't think my post was what I'd consider flaming. I did answer the question, buy stating that it varies quite a bit and then I made my point very clear - Fill up the car when it says to or sooner.

Could I have sugar coated it? Sure. But I didn't see a need to. And if you ready the whole post, you'd see that Harper and I have exchange some posts and all is well. No need to comment on this anymore.

 

You obviously don't understand why this topic comes up from time to time. Yeah, I'm sure there are some who want to see how far they can go before running out of gas. But I believe most of us don't want to run out of gas!!!!! It's not about pushing the tank to the limit. It's about understanding where the limit is so we don't reach it.

In your view, we should all fill up way before the last pip. Maybe that works for you, but for many of us, it's just not practical to fill up every time we reach the 1/4 tank mark. Keep in mind that the Prius gauge is just so different from traditional gauges. In my old car, I knew by looking at that needle when I absolutely had to get gas -- not that I intentionally pushed it that far, but sometimes it was just plain necessary. Understanding the fuel gauge in a car is an important issue, and the Prius gauge is hard to get a handle on.

I'll give you two scenarios where knowing the limit is helpful:

(1) Joe is on a long road trip. He's heading home for the holidays, and he's anxious to see the family. The 3rd pip disappears. Does he stop and fill up, when his destination is just fifty miles away? If Joe understood his gas gauge, he'd know whether he needed to put off hugging his mom.

(2) Jane's had an exhausting day, and it was a long drive home from work (she lives out in the country). She knew the gas gauge was getting low, but had decided to wait until the morning to fill up, since she likes to get her coffee at the local Quick Stop. While she's kicking off her shoes, little Timmy screams in pain. He fell from the tree he was climbing, and his leg looks broken. The nearest hospital is 50 miles away. Can she make it without stopping?

If you're tired of reading posts about the gas gauge, then don't read them. Skip them. Move onto the next post. Let someone else respond. The way I see it, if someone responds constructively to a question, then that question hasn't been asked too many times. So relax. It was just a few questions.

 

Or in my case, when the last bar is blinking when I have driven only 245 miles. I'm fairly confident I have 1/2 tank of gas left but fill up just in case.

 

So far my gauge is about as good as my past cars. When I get to the blinking last bar I know I need to fill up. My range at that point could be 15 miles or 70 miles and I can't tell. I think it is partly due to the tank shape. It is pretty big and too flat on the bottom. If it sloshes and sucks air the engine stops.

If I am on a trip and not sure where I can fill I normally fill up at the 2 bars point.

 

Ok, I like your scenarios.

1 This is fine, as long as Joe knows there's plenty of stations around. If he could end up going through the next 2 pips in 40 miles and there's no stations near home, he'd be wise to fill up - why risk it. I'm sure his mom will still be there.

2 Had Jane taken the time to fill up, she wouldn't have to worry at all as to whether or not she makes it. What if she thinks (based on past experience) that she can make it, but she was wrong. Now she out of as on the side of the road and poor Timmy is in agony.

The important thing for everyone to remember is that every Prius seems to be different. As Locke01 states, 245 miles and his pip is blinking! That sounds like a problem, but goes to show that the gauge can vary quite a bit. I think there's 2 simple things everyone can do to maximize driving and never run out of gas.

1) Fill up regularly. If you have an extra minute, stop and fill up. So what if you've only used half the tank. This way, you'll NEVER run into gas trouble. If I've used more than 1/4 of the tank, I'll stop, just if I see a great price

2) For those that want to push it or "know the limit", keep track of how much gas you put in on your previous fill up. If you put in 10 gallons and your MFD is showing 50mpg, you should be able to get close to 500 miles on that tank. 450 would certainly be a pretty safe bet.

And, as much as I'm sick of seeing all the posts on this subject, I will continue to respond, because I don't want to see anyone run out of gas!

 

Filling it at 2 bars or higher vs filling it at well below flashing could mean the difference of 2 or 3 hundred kilometers. With the rise and fall of gas prices here it could mean the difference of a few dollars which does add up over time. A few days ago, gas was 93.9c/L, I was sitting at 2 bars which will get me to work and back for about 4 days. Gas dropped down to 80c/L just outside the city recently. Filling up 43 liters at 80c/L is 6 dollars in savings.

I know from testing and advice from other Toyota drivers that when the fuel light starts to blink, there is 7 litres of fuel left. Due to the fuel bladder, that may mean as little as 5 litres left when the light starts blinking, so that can be used as a conservative estimate. I usually drive at least 90km before I start thinking about looking for a gas station.

 

I kinda like the way the guage works?.. If it actually was accurate to the last drop... we would miscalculate and run it dry!
I thought about keeping an emergency gas can in the back.. but those tend to give a little bit of lovely gas aroma.... yuk!
So instead.. just figure when the last bar quits, your empty and fill up before that... that gives you reserve that way.

Giving the gentleman the benefit of a doubt.. he may have not been enquiring with hopes to run it down to the last, but rather just to know what the limits are in an emergency.

I never run my car past the last empty mark "in my jeep", but I know it will go about another 40 - 50 miles past it... I just never excercise that option, because I don't trust it that well... but it's still good to know!

Since we are dealing with a car that will continue on battery alone and risk damage if it gets too low.. we have to take it more seriously and not run it down... and not play games with the devil.

 

I don't feel that Maytrix was rude, frustrated perhaps. Although his first sentence was quite cultivated AND I did not recognize one curseword.

 

Humm.. Too Bad.... A common mistake or oversight of a new member is that about 200 - 400 posts into a forum , they get most of our answers answered then don't have grace for others to learn the same thing they just learned?
What was new.. becomes old and were ready to move on. "Forgetting others explained to us the things "they" had already learned and read over and over and were bored of hearing over and over"

I"m a also a musician.... by the time my band and I learn a new song..we have already studied it, played it many times and are almost tired of it and ready to move on before we perform it the first time!.. If the audience loves it, then we "have" to play it more and more till we may be really sick of it!..

A reminder of why this forum was created "in addition to being a social gathering" is for #1. Learning... then
#2 Teaching... those who learn are taking from others.. those who teach are giving to others.. A mature tree produces fruit.... otherwise they only suck..... moisture and energy that is without giving back...

When have no grace to teach, we are only saying we are immature and its all about us. I am proud when I see the "Fathers" of the forum step up to the plate!

Where would any of us be out here without those willing to teach?.. and you have to admit.. there is such a mass and maze of different subjects and knowledge.. its hard sometimes to zero in on what your interested in at the time!

Not really something to be proud of.. in case someone thinks its cute.

So lets everybody kiss and make up and we'll get on with the gettin on!!!

 

I never fill till the last bar blinks. You can quote me on that. I read here of a simple and clear way to identify how much gas you have. And to paraphrase the original poster. For the sake of erring on the conservative, Assume that you put 10 gallons in when you fill. Then assume that your average mpg on the MFD is the number of miles you have once the gauge begins to flash. I set one of the trip meters then. And I fill after 20 miles or so of flashing. I have never run out of gas. I have only once gotten more than 500 miles per tank.

My impressions of fuel gauges are that they do not operate "linearly". There are too many variables in the formula. The length of the neck between the fuel filler door, and the top of the tank. Hey! It can hold fuel! So is that space computed in the fuel tank volume?

Who cares. Really. When it comes down to it. Drive as long as you feel comfortable. Then buy fuel. I can try and try and try some more, and I doubt that I can achieve the 600+ mileages per tank that some members report.

All I can tell you is that I get GREAT mileage in a car that has every option I have ever thought if. I have never been unable to merge onto a highway, or pass that drunk a**hole that is swerving in front of me.

 

Harper, It dosen't hurt to run the tank down to the last gallan. That's why we have fuel filters.

Maytrix, When the last bar starts blinking that's when I just keep driving. :lol: That was the first thing I did, push the limit of the fuel tank just to see how far I could go after the last bar starts blinking. for the recored I went 35 miles and put 11.229 gallans. almost all highway.

 

That's good info to know. Since I've read several of these threads, I already figured that out... but new people are posting here all the time. I'm sure these gauge questions will keep coming up, and coming up, and coming up. I've noticed searching the forums for a specific question can be time-consuming when I only have a generic search term (like "gas"). I didn't know "pip" until I read it on PriusChat (possibly reading one of your posts ).

Someone suggested in a recent thread somewhere that we need a "newbies start here" link to FAQs (like the Knowledge Base), along with a more in-depth FAQ section. A FAQ on the fuel gauge/tank would help.

(Danny, if you read this, I'd be willing to help.....)

 

Remember also that the tank is often hard to fill up, and also shows full when it is still about 4 gallons shy of full. This contributes to why some people only get 245 miles on a tank... They think it's full, and it isn't.

 

I would be willing to bet that just about everyone who complains about the inaccuracy of the Prius fuel guage never gave a second thought to the fuel guage of their previous car. It wasn't any more accurate, but people weren't sitting their comparing the instantaneously calculated MPG with the miles driven and the location of the fuel guage needle.

In your previous car, it was more of a binary thing. You would look at it and ask "Do I have a lot of gas or only a little gas?" or "Should I fill up today or can I wait until another day?".

So, pick a comfortable level, such as 1, 2, or 3 bars, and when you look at the fuel guage and ask "Should I fill up today?" then if it's at or below your comfort level, answer with "yes", otherwise answer with "no".

 

Yea... I bet your right, and 4 gallons is 150+ miles of driving?..
Its kinda hard when you have so many postings warning you not to overfill or cap the tank, yet based on how fast you fill etc.. it may stop prematurely.

I would think its best to stop when it stops "if" you were filling it at full speed, then restart at the slowest speed.. when it stops... then your done.. no more.

Maybe someone else who actually "owns" a prius can suggest!.... I don't have mine yet....

 

No other artifact I've owned has encouraged me so much to push it to the limit as the prius. Driving the car and the social order emergent around it (e.g., PriusChat) is a big video game. You put a friggin number on a screen, and most people are going to try to beat it, simple as that. XX.XX MPG, beat that. YYY.YY miles per tank, beat that. Make it talk in French, beat that. Easter Eggs, beat that. Ambient air temp effects, beat that. Hill slope angles, beat that. The car is just crying out for measurement and rationale of it's (and our) behavior.

 

Ha.. you made me laugh!... thanks!...
Human nature tends to be quite funny!

Its just our creative nature to always add to, and never leave good enough alone...

don't we make everything in our own image?... I wonder where we got that from?