gas meter weirdness

yup.

 

Hello,
New to the beast, and a dear beast it is.. so do not have input - but I do have a question along the same thread, as it were.
Have only had my -new to me car - for one week. First time going to fill up was today - And first time in my life I've ever felt excited about filling my car up with gas!
Anyway, there were two notches left on the gas gauge so thought it wise to fill up, not knowing more about the car. I stopped filling at the first click off on the handle, it only took 4.1 gal. of gas! Seemed strange and when I got into the car it only read three quarters of a tank of gas full.. not sure if the bars will climb higher in time as the above person, wfz, mentioned but seems unlikely it would climb that much higher (haven't counted the bars - sorry).
The other thing is that I know it can read full because when I got it from the dealer - it read full!
Does anyone have any thoughts as to why possibly it only took 4 gal.s? Should I have gone on beyond the click, which I thought was not good to do? Wait to see if the bars continue to show up slowly..?
2007 touring with 23000miles on it , temp outside 45-ish F

thank you
cheers

 

Try holding the pump nozzle at a different angle and go for a 2nd or 3rd click while pumping at the slowest normal speed. You will get a more consistent fill and won't overfill you tank as long as you don't dribble the gas in or keep on filling after a bunch of click-offs.

Edit: I hadn't noticed I was in the Gen II forum. Gen II tank filling problems have been discussed at length.

 

The OP does not say what year Prius he has - but it sounds like a Gen II (2005-2009). These cars have a bladder in the gas tank which can cause gas pumps to shut off before the tank is full. I find that this is particularly true in winter months when the bladder is "stiff".

I've also found that some pumps are more sensitive than others - it's all in the calibration of the "auto shut off" mechanism.

 

Some have found that resetting the "inclination-meter" will help to make the "guess gauge" more accurate.

Fuel Inclination meter reset | PriusChat

JeffD

 

Wfz, as mentioned above, the bladder in the fuel tank is probably stiff in cool and cold weather. Just got our '05 a few weeks ago and so far can't put more than 7 gallons in it, even with the last pip blinking. Although it does read a full tank on the gauge. They say that in warmer weather we should be able to put more fuel in. I too, was actually anxious to buy gas for about the first since I started driving 37 years ago JeffD, thanks for the link re: the Fuel Inclination Meter reset. I'll read that and check it out.

 

As many have said, the bladder in the Gen II Prius does cause problems at times filling up. One thing I found that really helped me is this.

Open the gas cap about halfway. Then go inside and prepay for your fill-up. Then go back out and fill the tank. If you are trying to use a credit card rather than paying cash, simply open the cap halfway then take the time to check the oil under the hood. By doing that you are allowing some time for the tank to vent.

To fill the tank, set the handle on the first notch and let the pump shut off automatically. Once the pump has shut off, hang up the pump. Then go back inside and get your change. Most of the time the tank will fill Ok if you allow the tank to vent BEFORE attempting to put fuel in it.

I have found if you simply take the cap off and try to fill the tank without letting it vent a little, the pump will sometimes shut off early and also sometimes the tank will not fill all the way. I have also found if you try to fill the tank at full speed, there will be occasions where the pump may shut off early or not fill all of the way. It seems that the slowest setting works the best.

Last point is this. When it is cold (winter time) the tank won't hold as much during the summer. This is normal. The bladder get's stiff when it is cold and won't expand as much as when it is warm.

Finally you will find that no matter what you do, you will never be able to put 11.9 gallons in the tank. I realize the manual says that is the capacity. Most folks find that a fill will be somewhere between 7 to 9 gallons of fuel if the guess gage is reading one pip or less.

Enjoy the mileage and your Prius. Compare what you are paying at that pump to the guy next to you with that big SUV or pickup truck. I think you will be pleasantly surprised.

 

oops, don't know how that happened..

Yes, I did fill at the slowest pumping.. and probably stared at the clouds long enough to let it vent but who knows, that sounds like my next thing to try - since I use a card. Hearing that most get 7 - 9 gal fill on possibly one blip left then maybe at two blips left (which is what I had) would be about right? That being only a 4gal fill.. and accounting for possibly not venting - may be the reason it only read three quarters of a tank? Ok, I'll take one step at a time and try this, guess I won't panic yet! I must say though, only putting in four gl.s was rather nice! But would like to fill it to full.
The actual temp was about 55F that day as it turned out so thought maybe it wasn't the bladder thing.. but who knows?
Loving this car at this point anyway!

 

It is very possible that the pump you were using did not operate properly and shut off early (3/4 tank on gage). Sometimes that happens. The only thing you can do is try a different pump next time.

If you continue to see the tank is not filling when the pump shuts off after trying a different pump, then try to reset the inclinometer. Some say that helps, others say it makes no difference.

On our Prius, if I fill at 2 pips I usually pump in about five gallons. Sometimes a little more, sometimes less. At one pip it usually comes around 6.5 to 7. The gage is not repetitive, that is why a lot of us here call it a guess gage. I have never ran it down to the flashing pip as some do here on PC.

Since you are using a credit card, try the following. Unscrew the gas cap halfway then go through the process of swiping your card. Since it takes time to swipe the card, enter the zip code, etc. the tank should have enough time to vent. By the time you get back to the pump handle it should be Ok to start filling the tank.

 

I read through the process of resetting the inclinometer - forget it! Don't think I want to attempt that.. besides, looked to me that there seemed to be a consensus it didn't make a difference.
No, I'll give your suggestion a try though, see how that pans out before I do anymore whinging about it.
Thanks so much for the suggestions all of you.
Now I have other questions that need addressing - but probably ought to find the right thread for them I suppose.
cheers

 

Read this thread. Explains why my first fill was only 7 gallons even though the fuel gage was only on one bip. Read full when I was done. Guess I won't be going 400+ miles between fuel refills. Good to know a "flashing" bip occurs when it is really empty.

 

That sounds completely normal. I've often had it take a while for the last pip to light up after a fill-up in cold weather. Also, 7 gallons is a very typical fill. It will usually be less in cold weather and more in warmer weather. I haven't gotten much more than 8 gallons in a fill (in the summertime).

With the Prius, it's good practice to line up a filling station when you get to 2 pips. The gauge isn't very accurate, the tank capacity is inconsistent, and you don't want to run out. Aside from the "stuck on the road" situation, the Prius can experience other issues when running out of gas, such as HV battery stress, error codes, and difficulty restarting.

400+ mile tanks at 2 pips are very possible, especially in warmer weather. Driving technique and route play big roles.

 

Mine does this too