Prius Fuel Tank

actually the problems you have filling the tank is normal for many. suggestion is to know about how many gallons you used based on the MFD. then slow to the lowest speed you can WITHOUT STOPPING about 2 gallons before you anticipate a full tank. this will help you get more in before the first shutoff happens.

the reason you dont want to stop is many pumps have an overflow sensor that can be filled when stopping. this can make the pump unable to restart again. if everything goes about as expected, just call it good. it wont be full full, but you will still get great range on your tank.

now if the additional range is desired and you feel that you should be getting at least a few more gallons in there, try switching to another pump. many have been successful doing this. personally, i dont feel its worth the hassle especially if moving the car is required.

 

Usually, when the pump clicks. I can load in at least another 5 litres (around a gallon and a quarter). I'll also pull the pump out a bit to help it with the clicking.

 

Also remember that the internal bladder seems to "relax" with use, but that cold weather tends to stiffen it up, lowering capacity. If this is a new car, you may be able to get more gas in as you keep stretching the bladder with each fill-up. But if it's a cold day, don't try to force too much more in, or you could overflow the tank.

A Prius driving 8000 miles emits fewer hydrocarbons than a cup of spilt gas. (from the HSD web site)

 

From my knowledge, this isn't a vehicle problem, this is a pump problem. I have driven all across the country and for some reason certain pumps in certain states caused this same problem for 3 different vehicles. Have you ever used this gas station before with another vehicle? It's sad, but some bad pumps end up spilling fuel all over the side of my car sometimes. I get so fed up that I swear never to go there again. Good luck!

 

Good point! - and this is why it is just not worth it to try to squeeze another half gallon in to a car that already goes a long way between fillups.

 

It's happened a couple of times with me. I just press the handle down and fill S-L-O-W-L-Y. Most of the time that works and it fills until it's full (with no spills).

 

DON'T FOLLOW THIS SUGGESTION IF YOU FILL UP IN CALIFORNIA!

About $3 worth of fuel (and 10,000 miles of air pollution?) gushed out of the filler neck when I stopped filling S L O W L Y, when the meter read 11.572 gallons. I thought "This station surely needs to get its meters recalibrated," when it crept past 10.5 (my guage had shown the last pink bar blinking for about 5 miles when I stopped for fuel). Pushing the hose spout back into the filler neck did not stop the gushing. Some vapor under pressure seemed to be expelled alternately with 4 - 8 ounces of raw fuel for several seconds. :blink:

My guess: the vapor recovery and auto shut-off valve are not able to sense the full tank when fueling extremely slowly, so the station's pump obediently stretches out the Prius' fuel bladder until its internal pressure equals the pump pressure. A sensor may prevent raw fuel from returning to the vapor recovery system.

 

I have had the most luck filling my tank on the middle setting of the nozzle. When I try to fill up on the lowest setting, the valve tends to shut off early. My car is an early 2004 model. I did not have the TSB done on the tank after reading Dr. Fusco's story and my dealer had never done one. I didn't want to be the ginny pig. I can live with going nearly 400 miles between trips to the gas station. The most gas I ever put in was 9 gallons. The car was new and I wanted to see how much I could put in it, especially after reading the Prius boards on over-filling the tank. Unfortunately, a little gas spilled. I have not made that mistake again. I'm okay with 8 gallons.

 

I have constant shutoffs when I fill starting at as much as 4 gallons from full.

I use the super slow technique, etc to get my tank filled and have had spills. But lately I have been able to fill up spill free.

Here in MA I have found super slow on the pumps also sometimes prevents a shutoff but it varies with the pumps.

My main anti spill techniques are to:

1 fill fast till a click off. Then fill med till click off.
2 Then I can go super slow or just keep letting it click.
3 either way I make sure to pull the nozzle and pause every .2 gal when I know it is near full.
4 I also listen closely and stop and call it full at any kind of sound change.
Sometimes it gurgles, other times it just changes pitch a bit. Either way I stop there.

No spills in the last 5 tanks or so, and it virtually always takes over 10 gallons.
My record was 12.4 about, when I pulled into the station on fumes.

 

ok i have to say that using my fill technique, i have never spilled a drop of gas. this idea of filling the bladder at low flow creating an over pressure in the system where gas must be expelled like an overweight balloon is preposturous.

if that is the case, one must look at the pump being used as it is has a serious malfunction.

 

I agree it is mostly a pump problem, but it is on a whole lot of pumps around here.
The best pumps seem to be the ones that pump slower even at the full speed but these are rare.

As for the spit back I have had it happen with rental cars, where I could care less about trying to fill it full. And these cars had no bladders. I think the only effect of the bladder is it spits back a bit more gas if it happens.

Also a mystery to me is why if I put in just the end of the nozzle and the return holes are outside the filler, the shutoffs often are reduced and I can fill it much easier. Seems like that should increase the tank pressure and make it shut off more often.

 

My theory is that the bladder creates more back pressure than the pumps expect so they kick off early. It would be better if there was a sensor that went into the filler pipe and shut off the pump when it became submerged (or some other bizzare method). Don't rely on pressure, rely on actual fill level.
Maybe in the future there will be a sensor in the tank or at the very bottom of the fill pipe that connected with the pump nozzle and would signal "full".
I wouldn't want to try and equalize the pump pressure with bladder pressure, a SURE way to get spit back.

 

I wish the Perma-Cap people had finished a Prius-compatible cap. I'd like to find out if it would hold back gasoline in a bloated-bladder situation...

 

I had the same problem as heimdm when I filled up my Prius for the first time yesterday. The pump kept clicking off, even when I was just starting to put gas in. I could get it to go for a bit without clicking on the absolute lowest speed (i.e. right when the gas started flowing) but it would always click off again. Finally I stopped at 7.5 gallons, since I had 3 bars showing when I came in anyway.

I attribute part of this to a new/cold bladder, but it's still a little frustrating, especially since I'd like to be able to manually calculate MPG, requiring accurate fill amounts.

 

Bionic - I've filled up 5 times, with 2 bars showing each time. My average # of gallons has been 7 - 8.8 gallons being the most I got in and 6.1 the least. I'm still tracking MPG on a "manual" basis -- actually a spreadsheet someone had posted.

Filling the car definitely has taken some getting use to!

 

Am I the only one who fills up so infrequently that it feels like a new experience every single time you do it? :lol:

 

Arg, today I overfilled! It happened once before when I was filling very slowly, the pump never shut off.

Today I filled up till it clicked off, using approximately the medium position. It didn't seem like enough fuel, so I let go for one more click. When I drove off, I noticed the top two bars were not lit up, so I went back.

This time I filled up more slowly, and carefully watched the neck to see or hear if it was filling up with fuel. As soon as I saw fuel rising up the neck, I shut off the nozzle and withdrew it, and a moment later a gush of fuel spilled out!

The nozzle didn't make a tight seal, and I could see the fuel rising up, so I wasn't pressurizing the system.

The strange thing is that the fuel gauge doesn't show any higher! Still two bars down, even though I added another 9 litres (approx 2 US gallons).

Outside temperature was -5 C.

 

do you have an 04? there was a gas tank fix for early 04's that you might want to check into