Filling Prius gas tank

<div class='quotetop'>QUOTE(john1701a @ Nov 25 2006, 07:37 PM) [snapback]354044[/snapback]</div>

John,

If that is true, why did my Prius run out of gas 14 miles after it started blinking? I have great respect for all your work on the Prius Forum and your website, but I get frustrated when told there is no such problem when multiple people report an issue. There is a problem, and it is not always the user. Yes this subject has been beaten to death, but I ran out of gas on a blind corner on a hill on I40 outside of Memphis. By switching the car on and off more than 6 times I was able to get it off the interstate.

I have no problem with users keeping on beating this subject until it is fixed.

Can anyone say they have had this happen to them with any other car? The only car I had this happen to me on was the original Ford Mondeo in the UK which was a known problem. Ford fixed it - anyone at Toyota with a red face yet? I mean, if Ford can fix such a problem, why can't to ever so great and wonderful Toyota?

 

<div class='quotetop'>QUOTE(Fatfenders @ Nov 27 2006, 08:52 PM) [snapback]354513[/snapback]</div>

When I had a 2004 Prius on a two day loan from a dealer last summer I did not even know about the bladder. After 300 km or so I tanked it up, and the nozzle stopped at 13 l. Should be fairly OK MPG, and I was a real first-timer, not knowing a thing about EV-mode or pulse and glide...


Next week my own Prius is due, and I do not expect any difficulties with gas filling or any other issue...

Below a picture of the demo-Prius in a nice place last july.

[attachmentid=6193]

 

<div class='quotetop'>QUOTE(Porridge @ Jan 8 2007, 06:26 PM) [snapback]372743[/snapback]</div>

Is there a calibrated on " " date on your dash? In manufacturing, a measuring device should never be trusted unless recently calibrated. Even if the device was recently calibrated, it could be wrong. If you were really concerned with your safety, then you would never let your fuel gauge go below 1\4 tank. Drive your car man!

 

<div class='quotetop'>QUOTE(Porridge @ Jan 8 2007, 07:26 PM) [snapback]372743[/snapback]</div>

There's nothing to fix. When the gauge gets to 2 pips or 1, buy gas.

 

The infighting is ridiculous... there IS a design flaw in the Prius. It's a MINOR flaw, but it's still a FLAW. The bladder should not exert more pressure out than a regular tank or it should have a sufficient pressure release to allow the tank to fill properly. In theory, this should be possible by just putting a small air gap hole above the filling area (but still covered by the gas cap for while the car is running), but I'm not a car engineer, so not certain if that would work or not).

In any case... stop being bitchy to each other! Yes, you should PROBABLY fill your car before it gets that close to empty. If you drive as much as many people here do (myself included), filling up more frequently is a pain in the nice person. Stop pushing YOUR methods on other people -- this is a car, not a religion.

Finally, if anyone from Toyota is reading (and we know you are) -- this is a problem you can fix. You may not be able to fix the cars already on the road -- but you can fix it on the new versions of the Prius as they are released.

As Xander Cage said in XXX, "Don't be a ..... ". You get the idea.

Joe

 

There are 2 things I think that people might miss. I have had the same thing happen and there are ways around it.

1) Don't "Deepthroat" the nozzle. Pull it back about an inch. The bladder expands and contracts as the fuel enters the tank causing shut off. Which leads to point 2.
2) Don't squeeze the trigger on the fuel yourself. Automatically fill with the safety on the slowest fill mode. (fuel too fast = bubbles plus bladder expanding and contracting in waves as the gas sloshes around)
3) Don't try to squeeze extra fuel in when it finally shuts off. What often happens is that you are able to squeeze in fuel but when you pull the nozzle out you get gas on your shoes.

It's not like your parents Buick where you give it hell and then top it off till you see gas seeping up through the hole.

My two cent worth.

 

This is the best post so far on this over-posted topic. There is a minor problem, and most of us live with it without much trouble, but it could be better.

1) I always "Deepthroat" the nozzle. I push it in until it sits on the stop. I tilt up the handle, forcing the filler down, although I don't know that it helps.

2) I always squeeze by hand. I start with the lowest hold-open setting, then switch to manual squeeze as I get close to the end of the fill. I run the manual squeeze a little slower than the lowest hold-open setting. My fuel gauge is consistent enough to allow me to easily guess the fill amount within a half gallon. Often I can guess better than that.

I do agree that you can go too slow by hand. With some nozzles, the auto-shutoff will fail if you trickle in the gas. I run the hand squeeze setting just slightly slower, but mostly I do it to be ready in case the nozzle doesn't shut off automatically. This is a habit I acquired long before owning my Prius. I had a few problems with bad nozzles with my Ford van, so I adopted this technique.

3) I agree with this. When the nozzle clicks off, stop filling.

Tom

 

This is, if nothing else, a fascinating phenomenon for me. The first time I filled up my new (to me) Prius, it filled approx. 10 gallons, and I got over 500 miles out of the tank, and refilled with a blinking PIP. The last time I filled up, it only filled up just over 6 gallons. I've driven around 290mi, and have 2 pips left.

I can't understand why I was able to put approx. 10 gallons in it on the first fill up, and only 6 on the second. I know temperature can be a variable, but it was in the mid 90s both times (summer in TN...ugh).

It almost seems like, theoretically, the "bladder" is warping inside the outer tank, and can't unwarp itself, and so it's not allowing a complete fill. Just a thought.

 

It IS warping itself when its on almost empty. The bladder has collapsed. Which creates trapped air pockets. When you begin to fuel it, it unwarps and releases air pockets which the pump see's as a pressure change and shuts the pump off. This air trapping is part of vapor emmision recovery and is one of the reasons this car is a zero emmision vehicle. They just got a little carried away with the vapor recovery.

Which is why if you get out of the car and begin fueling immed on fast it will shut the pump off or worse after you forced some fuel into it it will belch out alot of gas on your shoes.

The fix is easy and works everytime. It has nothing to do with the pump or the angle you pump at.

Just take the gas cap off and let the tank breath for 2 minutes. The bladder will relax. When you pull in for gas open the gas cap. Go inside and get a drink or use this time to check the oil.
Then pump gas on slow setting only. First time it clicks off hang it up. With one 2 pips showing you should be able to get at least 8 gallons regularly. Took me a while to figure it out but has worked fine for the last 3+ years. It never ever shuts off if you let it breath.

 

Thanks Ed, I learn something new on this site every day.

 

How to fill a fuel bladder... took me 2 (2003+2008) to figure this one. For both cars, I fill to cutoff and nurse in the last gallon to gallon and a half and after doing this for the past year or so I can say that the fuel "Bars" at this point are almost exactly 1 gallon. The down side is that last gallon as the bladder reshapes - very slow, but satisfiying when done. The up side is no Evap, no Charcoal filter, no Expansion tank to worry about, just pack it with fuel... and I mean up into the filler neck (it does not stay long because the bladder finds room, somewhere)... 2-bars, 2gallons, 5-bars 5gallons, 8-bars same.
Since I started this process I have seen last bar flashing one time, it took 9.9 gallons after 7 clicks.

 

JFidler & Others - There were some posts on this forum a while back talking about the risks of overfilling the tank. There is a purge valve near the top of the filler neck. If liquid fuel gets into that valve it can cause the system to perceive a fuel bladder leak or plug up the vapor recovery system. I don't remember all the details but I would suggest caution and not consistently packing it with fuel "up to the neck". Once the liquid level is above that valve it is at risk. It's designed to shut off the pump nozzle before the gas gets that high.

Can someone verify if I remember this correctly?

 

Ok, My bad... I over-simplified, no, make that way-over simplified the Evap-Control System. Let me make a couple of corrections… The “Bladder-System” does have expansion/Evaporative sensing for bladder leaks, system leaks and I did not mean to suggest overflowing the filler neck… It’s just that the last gallon or so takes sometimes a dozen or so “burps”, “automatic-cutoff” clicks of the fuel hose handle. After almost a decade of practice with my two Prii, we have never set a DTC error code (for the fuel tank) and the fill-ups are ALWAYS within about a quart of what is expected as indicated by the number of remaining fuel bars showing. That is a lot of repeatable, predictable behavior. This is true in the winter and summer, but it does longer in winter due to the reduced flexibility of the bladder. These are the smartest cars I have ever owned. 2003 w/130,031miles & 2008 w/71,000miles.

 

I just got my prius last week. The first thing I did was to fill it up the same way that I fill up all my cars. Wait until the nozzle shuts off and then wait a few secs for the fuel to go down the filler tube and pump the nozzle a couple or three times more until the tank is actually full.

So very wrong.
My new Prius threw up on me.
Seriously. After I did the above about half a quart of gas vomited out of the tank and onto the side of my brand new (used really but new to me) , just detailed Prius and not a small amount of it onto me as well. Thank you Prius.

From this I gathered that I would have to change my filling habits and after searching the forum I found out why. Yesterday I filled it up after getting down to one bar. It would only take 6.7 gallons. In an 11.9 gal tank? Seriously - Wth Prius??

So I've given up on "conventional" expectations about filling the tank and now just fill it until the nozzle clicks off and don't worry about how much gets into the car. One or two bars? Just fill it up with whatever it wants to take that day. I do not want my Prius vomiting on my shoes any more.

 

You did not read my post a few posts back. The one where I mentioned topping off WITHOUT VENTING results in the gas belching episodes.
Do that a few times and they have to replace the gas tank and that $$$ will be on you.

The Prius has a very extensive fume recovery system and they really got carried away with it so in order to make a simple gas fill up drama free you have to compromise there vapor recovery mission by letting the tank vent before filling.

VENTING THE TANK CLEARS THE VACUUM IN THE TANK AND ALLOWS THE BLADDER TO RELAX. TAKE THE CAP OFF AND LET THE TANK VENT FOR 1-2 MINUTES.
THEN FILL ON SLOW TILL THE PUMP CLICKS OFF. THE FIRST TIME THE PUMP CLICKS OFF ITS FULL. HANG UP THE PUMP.

DO NOT TOP OFF USING YOUR OLD METHOD AS YOU DID NOT VENT THE TANK AND YOUR FORCING GAS INTO AREA'S THAT HAVE TRAPPED AIR. WHEN THAT TRAPPED AIR IS RELEASED OUT IT COMES WITH ABOUT A GALLON OF GAS BEHIND IT. USUALLY ON YOUR SHOES.

MY VENTING METHOD WORKS EVERYTIME AND AT 2 PIPS RESULTS IN 8 GALLONS OF GAS EVERY SINGLE TIME. NO MULTIPLE CLICK OFFS...NO GAS BELCHING. IT HELPS TO NOT ALLOW THE TANK TO GET MORE EMPTY THAN 2 PIPS BECAUSE THEN THE BLADDER IS COMPLETELY COLLAPSED AND TAKES EVEN MORE TIME TO VENT.
ITS THAT SIMPLE.

 

The most I've ever put in my Prius after >6 years of ownership was 9.975 gallons. Don't expect to put in 11.9 gallons.

If you consistently run down to 1 pip and can only put in the 6.7 gallons or so, then it's possible your inclinometer needs to be reset. See
http://priuschat.com/forums/gen-ii-prius-main-forum/45425-gas-gauge-didnt-show-empty.html. (Warning: I've never done this nor seen the need to do it, on my car.)

 

Sweet tip - thank you!

 

Hi Diane,

As other's have written, the Prius will belch if you try to top it off.

I too agree that this is the best method. Try following this procedure, and I think you will find it will work Ok for you.

Make sure you understand this first and foremost: Due to the bladder, the tank will vary in gallons from fill to fill, therefore you cannot always expect to pump a certain amount. It will average out over time.

1. When you arrive at the gas pump, place the Prius in Park and completely power down.

2. Pull the gas cover release.

3. SLOWLY open the gas cap 1/2 of a turn.

4. Proceed to prepay for your fuel or swipe you credit card, whatever your fancy is.

5. Once you have prepaid, then remove the gas cap.

6. Insert the gas nozzle all the way into the gas fill neck.

7. Turn the pump on, and then using the auto fill shut off lever, set the pump to pump at the "SLOWEST" speed.

8. When the pump clicks off, remove the nozzle from the fill neck and hang it up at the pump.

9. Then place the gas cap back on the fill neck. Rotate the cap until the cap clicks "ONCE".

10. Close the gas cap cover and you are done.

TIP: When putting the cap back on, sometimes you have hold the tether while rotating the cap. Also don't let the tether get tangled up with the gas cap cover, as it will give you problems closing the door.

TIP: Offtopic concerning MPG. Due to the bladder in the gas tank, you can not get a accurate figure if you check each tankful like you would your older car (Vette). Because of the bladder, it doesn't expand the same way every time. To make a long story short, average your MPG over several tanks - five (5) or more and then you will begin to get a "GOOD" idea of exactly what MPG you are getting from your Prius.

Whatever you do, DON'T top off your Prius. As Edthefox said, you can damage the evaporative system easily and it cost's a LOT of money to fix it once you have done that.

In all the time I have ever refilled, the most I ever put in was 7 gallons and that was around two pips.

It is harder to refill if you let the gage get down to one pip if it is cold. Again it has to do with the bladder.

Welcome to the quirks of the machine, it takes time but you will get used to it. The main thing is to enjoy the ride and the MPG.

Good luck to you.

Ron (dorunron)

 

Have you tried using nitrogen?

 

So... for any helpful Prius advisors still reading this thread...

Today, I tried to fill my 2005 Prius for the first time. It was down to 2 pips. I put in 6.2 gallons, and that really did not seem like enough - so I squeezed in another 1/2 gallon before the pump cut itself off again. Knowing this thing has an 11+ gal tank, I was confused... but quit trying to put more gas in. Fortunately, I did not get any splashback/rejection of gas!

When I turned the car back on, I saw that the tank read full, all pips showing.

After reading this thread, I'm even more confused. (There are so many nuances to operating this vehicle; I had no idea!) Does the tank only accepting 6.7 gallons at 2 pips mean that it was not burped adequately before I started filling? Does this mean it is not really "full", regardless of what the fuel status appears to be?

(And at the next fill-up, I will certainly try some of these suggestions about letting the tank breathe longer before filling, and filling it slowly by hand or on the slower automatic setting).

Thanks in advance for your help!