Prius Bladder System-Tip to Restore Tank Capacity

<_< Quote: " I'm not concerned about vapors or the environment.. "

Why would a person with such an attitude buy a Prius? I would admit that ecology is only one factor in my decision to buy a Prius [with a 2007 Prius on order]. Other factors were fuel economy, technology, GPS navigation system, safety ratings and Toyota reliability.

 

<div class='quotetop'>QUOTE(Greenkeeper @ Oct 25 2006, 12:10 PM) [snapback]338027[/snapback]</div>

If the Toyota engineers are such geniuses, how come I can only put 9.1 gals in my 11.9 tank when the "add fuel" warning is displayed on the MFD? I would be perfectly satisfied with the fuel capacity if indeed I could actually use a reasonable percentage of the 11.9 gal capacity. Using the above number it means that over 20% of the fuel capacity of my car is unusable. Seems like a design flaw to me.

 

<div class='quotetop'>QUOTE(daronspicher @ Oct 26 2006, 12:39 PM) [snapback]338694[/snapback]</div>

Man, someone seems a little full of himself... i mean honestly, the engineers at Toyota all have years and years of experience under their belt, have been designing cars for a long time, and spend all day focused on it... can you say the same? Because really, thats all the "We are *not* smarter than Toyota's team of engineers." was saying. it didn't imply IQ, just ability to design a car.

For the amount of gas - an 11.9 gallon tank at 51mpg (the LOW end of the EPA rating) gives an estimated max distance traveled of over 600 miles. Lets compare that to the rest of Toyota's car offerings:

Avalon: 407
Camry: 444
Solara: 444
Corolla: 422
Matrix: 396
Yaris: 377


See the picture? Even if you reduce the max capacity with a shrinked bladder to 9 gallons, you still get 450 miles, which puts it near the top of their offerings, in terms of range.

Yes, they may have been able to fit in a larger tank. However, think about what that would imply: the tank itself would weigh more. the gas in the tank would weigh more. And as a result, you would loose a little in mileage. They designed it to be a high mileage car, which meant reducing weight wherever they could.

I still don't see the point of a "bulge" in the filler tube - it just doesn't make sense. saying you want a bigger gas tank is fine, one can understand that, even if there are some pretty good reasons against it. But a bulge in the filler tube just doesn't make sense - it's like saying you want to add a second gas tank inline with your current tank. why have two?!?!?

Finally, while you may not be terribly concerned about vapor emissions and saving the environment, you should realize that the car is marketed towards people who are. It's great emissions rating allows people in more restrictive states (like California) to live a little easier without needing to take it in for emissions testing.

If you want a bigger gas tank, go buy a Tundra - they fit a 26.4 gallon tank in there.

Finally, i doubt you would be "just fine" with your proposed solution. From the posts here in this thread, i get the feeling that you would be constantly trying to top it off to the very last to get that extra 10 miles in between fill ups, leading to the same complaints you have now. 600 mile range isn't enough... how about 800? 1000? where do you draw the line?

 

I agree. The engineers most likely know (and have their reasons) with ALL aspects of the car, especially with the design and capacity of the fuel tank. This is a life safety part which is not something that a junior engineer would spend a day or two designing.

I bet 10 to 1 the main reason the Prius does not have a bigger tank in possible liability issues. Sure added weight and a larger space would be needed to accommodate a larger tank but you can bet additional liability is the driving factor.

Suppose the Prius gets into a terrible accident and the gas tank erupts in flames burning the occupants of the car. A lawyer could argue the Prius had an "unusually" large fuel tank for its size. "Ladies and gentlemen of the jury, when most consumer autos go somewhere between 300-400 between fillups, why such a a large tank to go 600 or more miles? It's a hazard, it's dangerous and that's why my client is injured!"

My former F-150 held 30 gallons of fuel. Enough for a comfortable 400-450 miles between fillups. Looking underneath the body and bed Ford could have easily fit another 20 gallons or so. I would have loved it but 50 gallons of fuel onboard? Guarantee Ford would be paying in the courts for that when the trucks crashed and burned (and they do; mine burned up all on its own).

Or more people may be caught dozing and crash behind the wheel of a 600-800 mile range Prius during a long distance drive. Sounds silly? Corporations have been successfully sued for even more outrageous reasons.

And don't try to be logical and say the 9 gallons is probably just a dangerous as 15. Perhaps so but get a $300/hour lawyer on your side... and you could even convince a jury a nice hot cup of coffee is dangerous.

Rick
#4 2006



<div class='quotetop'>QUOTE(eagle33199 @ Oct 26 2006, 02:39 PM) [snapback]338739[/snapback]</div>

 

<div class='quotetop'>QUOTE(ScottY @ Oct 24 2006, 02:47 PM) [snapback]337538[/snapback]</div>

Works for me.

 

I believe that ALL Prius owners who have had fueling problems of any kind need to report this to their Toyota service department while the car is still under warranty!
See my post here for details of my experience:
http://priuschat.com/index.php?showtopic=2...pid=341849&

 

<div class='quotetop'>QUOTE(Charles Suitt @ Oct 26 2006, 01:05 PM) [snapback]338711[/snapback]</div>

I think it's freakin' great. We need people that don't give a crap about the environment buying environmentally reponsible products.

 

<div class='quotetop'>QUOTE(adammc @ Nov 1 2006, 04:25 PM) [snapback]342163[/snapback]</div>

That is fine.
As long as they are not permitted to reproduce.

 

<div class='quotetop'>QUOTE(Actual Mileage @ Nov 1 2006, 06:14 PM) [snapback]342192[/snapback]</div>

lol.

Hey, too many petro vapors and Im sure your sperm count will decrease.

 

<div class='quotetop'>QUOTE(mikel 52 @ Oct 25 2006, 10:03 AM) [snapback]337976[/snapback]</div>

I had one of those. Mine had the stylish and popular for the era 'pop-off' type gas cap. Unfortunately, the hinge was at the bottom so when the gas tank burped it would fill up the pop-off lid like it was a little cup. Then, when it was closed, all of the fuel that had accumulated in the cup would run out onto the bumper and lower valance panel.

As to curing the problem on a Prius, I like the idea of using a spare cap with an air valve to put compressed air into the bladder to expand it to its maximum size just prior to filling up. If Toyota had been really clever, they could have made such a system integral, so in addition to solving the fuel bladder contraction problem, there would have been a way to put air in the vehicle's tires, bicycle tires, etc.

FWIW, I'm certain everyone is well aware that the Euro/Japanese Prius does not have the fuel bladder but just uses a standard fuel tank. If someone were hell-bent on solving the problem, they could make the effort to procure the Euro/Japanese fuel tank and replace the US fuel-bladder tank with it.

 

<div class='quotetop'>QUOTE(eagle33199 @ Oct 25 2006, 11:15 AM) [snapback]337987[/snapback]</div>

I was wondering if you have to reset the check engine light, and how do you do this? I mean after filling the gas tank.
Mary

 

<div class='quotetop'>QUOTE(galaxee @ Oct 25 2006, 11:04 AM) [snapback]338021[/snapback]</div>

Yup. The tech training from the techinfo site has about 20+ pages on just the gas tank and associated emissions system. Here are a few tidbits:

A pic of the cutaway tank showing the bladder:
[attachmentid=5855]

A diagram of the system with som interesting info on how the inclination sensors can get screwed up by filling the tank on a steep incline:
[attachmentid=5856]

Fuel capacity considerations and some stuff about the energy monitor requiring up to 6 weeks to accumulate "historical data" after a battery disconnect!
[attachmentid=5857]

Finally, a diagram of the incredibly complex filler neck and evap system for the tank. The charcoal canister has a cut off valve to help keep gas out of it, but repeated overfillings can overwhelm the system:
[attachmentid=5858]

The gas is inside the bladder BTW.

- Tom

 

Seems to me that as soon as you start adding fuel the bladder will assume the same temp as that of the fuel. I don't think there is that much of a temp difference between fuel stored underground year around. I don't know so if someone wants to measure it by all means go for it, I'm not really interested in doing it. Seems to me another way to test this theory would be to fuel up and measure how much you get into the tank over say a 5 or 10 times fill up and then do some fill ups with say room temp or warmer gas.



Wildkow

 

<div class='quotetop'>QUOTE(Tom_06 @ Dec 7 2006, 08:56 PM) [snapback]359097[/snapback]</div>

Tom,

Thanks for posting this. It's really great to be able to see these diagrams and photos.

 

<div class='quotetop'>QUOTE(adammc @ Nov 2 2006, 08:41 AM) [snapback]342450[/snapback]</div>

New birth control method?

 

<div class='quotetop'>QUOTE(pault842 @ Oct 26 2006, 01:28 PM) [snapback]338733[/snapback]</div>

Seriously, I would LOVE it if I could get 9.1 gallons in mine. Ever since the weather got cold, I can't get more than 5.5 gallons in it, even when I get the gauge down to 1 bar. The most I've ever gotten in it was 8.1 gallons. I am filling up around 225 miles or so, given that my MPG has sucked (low to mid 40's) since the winter gas came out.

 

<div class='quotetop'>QUOTE(Tom_06 @ Dec 7 2006, 05:56 PM) [snapback]359097[/snapback]</div>

Tom, et al, I accidentally (on purpose) ran my 06 out of gas and the pump clicked off at 10.2 gallons, so I trickle filled up to 11.7 gallons (no burping or spillage). By doing so, did I saturate the charcoal canister or am I still operating within design limits for the tank system? (Btw, I'm in SoCal, so no cold temps.) From this experience, should I usually be okay by adding in an additional gallon after the pump trips, since I'd still have something like 1/2 gallon under the tank capacity, as a margin of error for differences between pump mechanisms? It's not that I mind visiting gas stations (it's waaay better once every 6 days, rather than every three days with my Mazda RX-8!), just exploring the safe operating limits of this remarkably engineered vehicle. TIAFYH

 

Unless you are having a such a big problem and are short MANY gallons on a fillup (something might really be wrong), trying to defeat the Prius' sytem for and extra gallon of gas is ridiculous. Let the car do its job! Keep the vapors out of the environment. There are many things you can modify on your car that are more sensible, fun, and worthwhile!

 

<div class='quotetop'>QUOTE(MPG > HP @ Dec 10 2006, 12:08 PM) [snapback]360100[/snapback]</div>

I can only put in about 1.1 gallons in now after the click instead of 1.5 in warmer weather. 58K miles with no issues (except for steering wheel leaning slightly left), and I fill up every 7 days.

It's kinda funny my writeup on Wikipedia, composed from many threads off Priuschat, is now sorta gospel ...