my bladder is full

You should never top off the tank. Overfilling can damage emission control components. The best thing to do is set the pump on slow fill and stop at the first click. I use this method and it works fine for me and I try to not go below two pips before filling up.

You can still get a good check on your mileage if you average the results of several fill-ups.

 

The onboard computer is all you need to accurately calculate mileage.

 

Don't top off the tank. You are never going to know exactly how much fuel is in the tank at any given time, so stop worrying about it. Manual mileage calculations only work with the Prius when done over a large number of tanks, which distributes the error over a large number of gallons. Short term, use the mileage display on the MFD.

Tom

 

Stop topping the tank off. Hang it up when it clicks off the first time. I have had good results after my first gas belching episode (which you are on your way getting) with letting my gas tank vent. When I pull into a gas station I open up the tank cap. Let it vent for a few minutes. Go inside while its venting and get a drink then start pumping when you come back out. I know this is counter to the EPA fume recovery that its important to its zero emissions mission but it seems Toyota did not figure in what happens when the bladder gets slightly old and less flexible. Most gas belching episodes happen at around + or - 5K miles.
While filling up I do some math. If my odo says 350 miles since last tank and it says I av 50 miles to the gallon I know I shouldn't be putting in more than 7 gallons. I put the gas in slowly and put in 7 gallons. After you do this routine a few times it evens out to correct math and then its easy. And non episodic. And works. Good luck. It takes a tiny effort to get 50 miles to the gallon. This is it.

 

edthefox5, that's great advice. I never let my pips go below 3 or 4 before I fill up. But I like the idea of using 50 miles a gallon to guess how much gas I used. I should of thought of that.

 

Does the MFD not give you gallons used? SGII does, right?

 

If I fill up at 4 pips, I'm, lucky to get in more than 4 gallons!

 

I have had my Prius for a while now and it never fails to amaze me that folks want to out guess the bladder (being an older woman and having had a child, I never outgess ANY bladder). I worked with a psychiatrist who ran out of gas so often with his Prius that it got to be a running joke.
When the car flashes that last pip at you, go get gas. The last time Dr. K ran out of gas, he pushed the car into the gas station, ripped the achilles tendon in his ankle and required surgery.

 

I've been having problem with the nozzle constantantly clicking off. It will literally click off every couple of seconds, starting right away, and is a PITA to refill. I assume the elastic bladder is creating back pressure that is the tripping the nozzle. I've tried the nozzle all the way in, half in, just the tip in, rotated 90 degrees, pump slow, pump fast, nothing works. Anyone else experience this when the car is new?

I have no idea when the bladder is full because of this. Like others have said, I try to approach the pump already knowing, based on consumption, how much gas it needs.

 

I've seen on some postings that the tank is actually only 10 gallons - which I personally beg to differ. I was down to one pip (not flashing) on my last fill up and put in 10.186 gallons.

I would agree that you should not overfill any gas tank - bladder or no. You just don't need the potential damage to your car's paint or the environment just to get a few extra drops in the tank. Just my 2 cents...

 

Never, Never top off tank. It will spray at you when you remove pump nozzle.

 

The fuel tank gross capacity is 11.9 gallons, as clearly stated in manual. As posted on this forum a gazillion times, the fuel tank bladder reduces the usable amount of fuel by an unpredictable amount, but it usually ends up somewhere in the 10 to 11 gallon range. Many of us suggest using 10 gallons as a safe figure, since the usable amount should always be at least that much.

Tom

 

Hi Qbee42! Thanks for your post. It sounds like some may think the gas goes into the bladder, instead of the bladder being used to fill void in the 11.9 gallon tank. Quick question. I think I understand the workings of the bladder, but I'm not clear in your suggestion to "use 10 gallons as a safe figure". To "use it " in what context? To guesstimate miles to empty?
Thank you in advance for any reply.

 

Funny, my bladder seems to be shrinking with age, too - or maybe it's just losing it's elasticity. I'm not looking forward to the recall notice, either, and following the instructions in the technical service bulletin provided only temporary relief.

 

Hi Dave,

I believe the suggestion is to assume that you have no more than 10 gallons in the fuel tank after you have refueled. Hopefully you actually have more; but you may not.

 

Exactly, that's what I meant. Having a little left in the tank is no problem; not making it to the gas station is. Even a tank with an old bladder in cold weather should hold at least 10 gallons of usable fuel when it is full, so I use 10 gallons as my full tank figure for quick mental calculations.

Tom

 

Sounds good!

 

I learned immediately that the fuel tank could only take fuel at the nozzles slower setting. That way sometimes I'm done with the window first but not very often. I have learned that the manual's stated 3 gallons of gas at fuel tank blinking is a joke along with any support from Toyota. I believed the manual's statement about 3 gallons but discovered that it really means YOU ARE EMPTY and if your not in the driveway of a gas station look out. It cost me about $280 for the tow, motel and service. The folks at the magic number for complaints have a rather poor approach to customers. The manual "Its printed in Japan we're not responsible for it"
And then there's the 12v battery that will run down to dead if you don't drive the car for a less than a pair of weeks. All in all not a very well design for several of the areas. I do get 48 mpg on the highway and have gotten up to 57 mpg out of at least one tank full. So I guess there's good and bad.

jack999

 

Looking at the way the whole vent system is designed (horrendously complex for a consumer device) it sounds like something is obstructed or you have a seal leg of some sort.

I would expect that a fully inserted nozzle with a good seal on level ground would fill without trouble as long as the pump was not entraining a bunch of air (that would be a problem.) Slow fill rate would be a plus as it would allow more venting through the canister without creating too much backpressure. If however, one of the several vapor lines or canister is obstructed/restricted or if the fill rate was high then one might expect the back pressure to shut off the pump quickly. I'm not sure what happens if a bunch of gasoline is ever forced into the various vapor lines, but I suspect it is going to result in chronic problems.

The system appears way over engineered in efforts to reduce emissions from filling. I would much prefer a normal tank system with the same capacity as the current Prius. It might be worthwhile for someone to implement a vapor bleed system for the tank when filling. This would completely defeat the bladder, but I really don't care if it consistently works properly.

Haven't had the problem myself, just trying to get up to speed.