My tank is only 5 Gallons

[grinthock]

I know people have tank issues - but I am trying to figure out what mine are.

Down to 1 pip, (and driving on that pip for some time) I was able to squeeze in 20L (5Gal) that's it.

Is something wrong here? My book says my tank is 44L in capacity, yet from empty to full is 20L?

should I be going back to my dealer? Any tips to help "expand" the bladder?

[Patrick Wong]

Hi Justin,

A few questions:

How many times did the fuel pump click off while you were pumping 20 liters or 5 gallons?

What level did your fuel gauge read after refueling?

Perhaps you should try pumping an additional 10 liters?

[grinthock]

Sometimes the pump is hard to get going... so i squeeze it in slow for a litre or two, and then pull hard and it pumps like normal. It didn't shut off till the 20, and then i squeezed a little and it immediatly clicked off so I stopped.

It showed full.

Try pumping in 10 more? No way that would be possible.

The catch 22 here is, people say don't top off, but yet it's not filling all they way...

[Patrick Wong]

If your gauge is showing 10 bars then you're right. Might be possible to pump 4-5 liters more but 10 would be asking for trouble. Guess your fuel tank bladder becomes really small in the frigid Canadian winter.

[grinthock]

I'm in Ontario - it's not that fridgid here.. right now it's probably 28-34 degrees daily.

What I have thought about is filling it -- driving a bit - and filling again, perhaps the weight of the fuel sloshing around is enough to expand the bladder.

Something tells me the bladder edges stick togeather when the tank gets low.

[morpheusx]

That may help, on occasion I have only been able to get about 7 gallons in from empty (when its cold), but can't put anymore in. The gauge will read 10 bars, I'll only drive say 10 miles or so. The gauge will occasionally just drop a bar while parked when this scenario happens.
I have previously read on here somewhere where some guy claims he unscrews his gas cap then washes his windows then he pumps his gas, he claims it lets some of the vapors escape and is able to pump in 11 gallons or more everytime.

[Celtic Blue]

It's a pretty odd tank, that's for sure. Although my fills have been trouble free so far (fill at 1 pip/rarely 2, lowest nozzle setting, off at first click) I don't doubt those who see these problems. For me one tank is 8.7 to 8.9 gallons but the next might be as low as 6.3 (from what I've seen so far.) Some of this is whether I fill at 1 pip or two, but the calculated/vs indicated gasoline usage for these same tanks varies from nearly a gallon under to nearly a gallon over (1.9 gallon variation). 20% variability on the tank is borderline at best.

If I was only getting 5 gallons in from 1 pip, then I would take it to the dealer and document the problem and see if they could find any thing. Assuming nothing changed and the problem remained, next I would probably try packing that sucker to see if I could get the bladder re-expanded. If it has problems after that it is Toyota's problem. It is after all a problem with the design and/or manfucture to begin with. The more outlay they have for improperly functioning tanks, the less likely they are to adorn future Prius' with this unnecessary albatross.

There is a lot that can go wrong with the complex vent system for the tank. The line sizes appear to be too small for the vapor traffic and the design is likely to produce two phase flow choke points during the fill. Adding to that it wouldn't surprise me if ice restricted a line at some point.

[qbee42]

You may need to have your tank level reset. The dealer can run it through a simple process on a flat surface which will reset the inclinometer on the fuel gauge (you can do it yourself if you wish - the steps are on this site). If the inclinometer is off, you can get a premature empty reading, meaning not as much fuel will go into the tank when you refill from "empty".

Tom

[grinthock]

Last night, I went out and had only 1 pip gone - and put in 10 litres. So let's see what kind of mileage I get on this tank now.

[brick]

Originally Posted by qbee42

You may need to have your tank level reset. The dealer can run it through a simple process on a flat surface which will reset the inclinometer on the fuel gauge (you can do it yourself if you wish - the steps are on this site). If the inclinometer is off, you can get a premature empty reading, meaning not as much fuel will go into the tank when you refill from "empty".

Tom

This is exactly what I'm thinking. Filling only 5 gallons from the 1-pip mark is pretty extreme even for our finicky cars. The fuel gauge may be reading low.