NO fix for Prius Gas Tank Filling Up Issues

[PaulHS]

Originally Posted by qbee42

My general concern would be the effects of over-pressurizing the fuel system.

Yes. One would have to be very "gentle" applying the air pressure and there would have to be a clear-cut way to measure any positive effect on the bladder. (?)

First you would need to command all of the fuel system valves into the correct position, then apply enough pressure to stretch the bladder without damaging any of the valves, fittings, or emission system components.

Guessing here: With the car turned off - just as when filling the tank, it would seem likely that the valves would be in the correct positions by default. But you are certainly right about potential damage.

The bladder doesn't have much room to move, so it's hard to imagine being able to expand it enough to make much long-term difference.

Well, in my case, there must be room for the bladder to expand by roughly 4.5 gallons. That's not insignificant. I agree that the long term aspect of the exercise may be debatable. I do wonder what is the mechanism that, up until now, has reduced the tank volume by such a large amount. Summer and heat have arrived and, if flexibility is the only issue, I would have expected to see some measure of expansion by now, but there's been none. In fact, my last three fillups have been a consistent 7.4 gallons.

It sounds like a lot of bother and risk for not much return.

Tom

At this point, with no sign of input indicating that the process has been attempted, all we have is a thought exercise. I won't make my Prius the guinea pig!

Thanks, Tom, for your thoughts and cautions regarding the idea.

Paul

[donee]

Hi All,

Actually, I think sucking any residual air out might be the solution. Because as the gas fills, some might get stuck in a portion of the bladder away from the filling tube. Kinda like air trapped in an underwater cave where the entry is lower than a portion of the cave.

This would explain while waiting and driving around fixes it. The gas sloshes back and forth, and the air buble gets moved over to the filler tube end of the bladder.

Sucking on a near empty tank would then pull most of the air out, which would then cause the bladder to be squeezed flat by the outside air pressure. When gas if pumped in, there is very little air space.

The only problem with this is how to suck on the filler tube without pulling out gas as well.

Maybe there is an air valve on the metal tank? Then one could hook up a foot pump to it, and open it. With the gas cap off, one would pump on the foot pump, pressurizing the metal tank, until gas comes up to the filler neck, but not out. Then turn off the valve and remove the pump. Put a pump nozzle in the filler neck, and slowly pump in gas as the valve is released. This fills the bladder with only gas.

Anyway, its a bit of guessing in this. There has to be a proceedure done at the factory to address this issue. I just wonder if it can be replcated in the field.

[diamondlarry]

Originally Posted by qbee42

With this much fuel you are risking damage to the evaporation canister, or worse yet, fuel outside of the bladder, which will necessitate a replacement of the entire fuel tank assembly. It's an expensive repair, and not covered by warranty, so be careful with over filling.

Tom

I have heard of that possibility. I have 20K+ miles on the odo and done this since day 1. As I have mentioned in another thread here, the fact that I have 20K+ miles and no problems, suggests that the problem is either rare or there is something about the way I'm doing it that is keeping it from happening. As always, YMMV.

[9G-man]

Originally Posted by dar

I do understand that the tank is rated at 11.9 gallons. I know that I will never get 11.9 gallons of gas in the car, that is not my concern. My concern is not knowing how many gallons of gas are in the tank to even guess a driving range.

Sorry you are dissatisfied with your Prius, but I'd like to help.
This car impresses me daily, and I want you to be delighted with your car as well.

As we all know the Prius gas tank is a little different. Here's how you handle it.

When you get gas Always reset your consumption display at each fill up. Also, Note # of gallon you pumped to fill up.

First, when it comes to range, the most important rule is:
You only have as much fuel in the tank as YOU'VE pumped in.
To figure your range, simply divide your average MPG into the miles you've driven since last fill-up.
When the figure approaches the gallon you pumped, it's time to fill-up.
Or another way...Multiply your average MPG, at any point, by the gallons you pumped, and that's your anticipated range. When you've driven your anticipated range, get gas.

When it comes to pumping gas into the Prius, there is something you should know.
There is a small rubber sealing ring inside the Prius' gas fill-pipe. It seems to cause the tank to pressurize when gas is being pumped and causes the "burp" many complain about.
To eliminate the "burp" or backflow of fuel during fill-up, always remove the pump nozzle from the car's fill-pipe for a few seconds, when the pump stops, before you try to pump some more.

Follow these steps to get the most out of your fuel tank:
Drive your car until the low fuel warning comes on, and go to gas station.
Reset consumption display.
Fill up on slowest pump setting. When pump stops, remove nozzle (for reason noted above) , then pump some more. Repeat until you've pumped 1.o more gallon.
I guanantee you've got at least 10 gallons of gas in the tank.
But to be safe, go drive until the low fuel warning comes on again, or you've driven 9x your average MPG since fill-up. If the latter occurred,
I guarantee it will take 9 gallons to fill up
Do it again, if the low fuel light doesn't come on, drive 9.5 x average, or 10 x, etc.
Whenever you fill up it will take that many gallons.
Reach the point where you are pumping 10-10.5 gallon at fill up and you've maximized your tank, with some reserve.

Now relax about the fuel tank, and lenjoy having the best car on the road.
Next, Learn to drive the car, to get the most efficientcy out of it. To maximize the time it spends on electric power. It's all in your right foot. Then, you can too can get at least 600 miles out of every tank like I do.

[ranchogirl]

Does the 2005 have this issue? We have a 2005 and to my knowledge, this has never happened.

[9G-man]

Originally Posted by ranchogirl

Does the 2005 have this issue? We have a 2005 and to my knowledge, this has never happened.

Yes, the US (NorthAmerican) Prius have the bladder gas tank. It's not an issue for me either, I had it "burp" once in the beginning and just slowed my pump rate and remove the nozzle sometimes as i describe in above thread.
I pump over 10 gallons everyfill up and drive over 600 miles/tank.

[ctsa]

I drove my '08 off the lot a week ago today. I am having nothing but problems trying to put gas in. I have tried several stations in and out of town. I made a 450 mile round trip this weekend out of town and visited several different stations. Each time, I had the same problem. I am forced to try to get gas in by one little blip at a time. It will never stay on long enough to try to put it on the lowest setting. I barely pull the trigger and poof...off it goes. Additionally, after 840 miles of driving...the fuel guage has never had more than 1 pip off the screen. In other words, it has always showed me full even after 300+ miles of driving.

Obviously, some of you have not had this problem and continue to reply on this post as if the OP and the rest of us with this problem are idiots. Instead of adding to our frustration with comments like "I need data, perhaps you should simply add up the .127 gallons you get in with each blip and sit at the gas station for 3 hours. What is the big deal?"

Why don't the rest of you who don't experience this problem leave it to those who do to discuss? I have not found anything that works, but I am sure interested in hearing what people who have my same experience have been successful doing. I don't much care to hear from someone who has no problem at all as if it is because they are superior gas pumpers instead of just damn lucky.

[qbee42]

I wonder if different areas of the country present more problems with Prius fueling. For example, where we live the gas pumps are fairly simple affairs, without any sort of vapor recovery. Other places use more complex pumps. Maybe we need a survey, but it will be hard to factor out Prius density for the various areas.

As for all of the potential Prius owners reading this thread and wondering if this will be a problem for them, I'll add my one data point: I've never had any trouble refilling my Prius. I insert the nozzle and set the rate at the lowest setting. When I get within a gallon of my expected fill I unclick from the auto-fill detent and go a little slower by hand. When the pump clicks off, I stop. The only reason I use manual fill for the end is because of problems I've had in the past with a previous car. Having the end fill under manual control lets me stop faster if there is a problem.

Tom

[dar]

[quote=9G-man;656488]Sorry you are dissatisfied with your Prius, but I'd like to help.
This car impresses me daily, and I want you to be delighted with your car as well.

As we all know the Prius gas tank is a little different. Here's how you handle it.

I do know how to calculate gas mileage ... pretty basic math and work with the electronic system! I am not an idiot ... I am VERY dissatisified with my 2008 Prius and I have been trying to speak to others that have been dealing with this issue. I am getting a bit tired of owners using this forum to personalize and belittle this issue. Those that are doing this, have not NOT expereinced this issue.

I am VERY happy for ALL Prius owners that are NOT experiencing this issue ... consider yourself fortunate ... if you have not had this problem, you do not need to continue to badger those of us that have.

This specific issue has NOTHING to due with an individual gas pump, yes pump flow is an issue. Some of us, no matter how SLOWLY gas is pumped into the tank ... the tank is "full" far too soon. Also, Toyota Corporate has admitted in writing ... this issue is due to a DESIGN FLAW, the bladder and 6-7 gallons is a "normal" fill up.

Toyota does encourage owners with this issue to contact their corporate office in California. You can also write to the BBB and the National Center for Dispute Settlement regarding this issue.

Looking at the posts, there is truly NO FIX for Prius gas tank filling up issues. No one has a neat trick that makes fueling easier ... you either can "fill up" ... the majority seem to go with the first click 6-7 gallon, a few seem to get 10 gallons in ... and there are those that cannot even get the 6-7 gallons in their cars.

[qbee42]

[quote=dar;658002]

Originally Posted by 9G-man

<snip> Looking at the posts, there is truly NO FIX for Prius gas tank filling up issues. No one has a neat trick that makes fueling easier ... you either can "fill up" ... the majority seem to go with the first click 6-7 gallon, a few seem to get 10 gallons in ... and there are those that cannot even get the 6-7 gallons in their cars.

When discussing the number of gallons required to fill up, let's not forget that it is also a function of the number of remaining gallons at the time of the fill. This in turn is a function of gas gauge calibration and how long you wait before refilling. I typically refill at around two pips, which with my Prius means I put in about six or seven gallons of fuel. On the times that I let it get down to one pip, I put in over eight gallons. I have never let my Prius get down to the flashing fuel warning stage, so I don't know how many gallons it would take to fill from there.

The fuel gauge can be recalibrated if necessary.

Tom