Extending Range - Adding Aux Fuel Tank

<div class='quotetop'>QUOTE(faith2walk @ Apr 21 2007, 09:58 PM) [snapback]427582[/snapback]</div>

You should be doing a little better. What sort of trip distances? Do you carry much in the back?

<div class='quotetop'>QUOTE(faith2walk @ Apr 21 2007, 09:58 PM) [snapback]427582[/snapback]</div>

There are some pretty impressive, metal fuel cans available. If you could strap it somewhere so it won't risk tipping, spilling or solar heating, carry the can?

A second option is to get a receiver hitch and carry the gas can on one of those oversize platforms. This has the advantage of getting the attention of a tailgater. Heck, you might even add a few lights to make sure they see the 'horribly explosive' gasoline can even at night. <grins>

I'm not sure a can in the spare tire well makes a lot of sense. As you've already realized, there would be plumbing and access issues.

GOOD LUCK!

Bob Wilson

 

<div class='quotetop'>QUOTE(faith2walk @ Apr 21 2007, 11:56 PM) [snapback]427658[/snapback]</div>

Feasible?

Probably.
You would just have to maintain vacuum.
Another bladder hooked up, maybe???

Dangerous?

e^(lot more than probably).
Unless you encased it in steel.
And wore a fire suit.

 

Keep in mind that you'll also take a MPG hit for the added weight of carrying the extra gas.

 

The problem you face is that the gas tank contains a flexible bladder whose purpose is to prevent evaporation, thus reducing pollution. Tapping into that would be problematic. The easiest thing would be to carry a spare gas can, as bwilson suggests, but that raises safety issues. Do you really want gasoline all over the place if you are rear-ended? Do you want gas fumes inside the car from a gas can inside?

You could probably install a gas tank in the spare-tire well and have it vented to the outside, with a small hand pump to pump it into the car's tank. You'd lose the benefit of the gas bladder in the main tank, because now you'd have evaporative emissions. And you'd have to deal with the gas-soaked hose you'd use to pump from the spare tank to the car's tank, unless you installed permanent plumbing between them with a sealed valve. All in all, I think it's not practical.

Personally, while I think you could extend your range, I also think you're better off just to stop every 300 to 500 miles to fill up at a gas station.

And BTW, I used to live in North Dakota, so I know what you're talking about regarding the temperature extremes and the winds. I think your numbers sound about right to me.

 

<div class='quotetop'>QUOTE(faith2walk @ Apr 21 2007, 11:56 PM) [snapback]427658[/snapback]</div>

I'd like to suggest an engine tachometer (not trivial for a Prius) and drive within some rpm limits. Several of us have found staying below 3,200 rpm helps a lot and it is even better if you can stay under 2,400 rpm. These limits are possible even for most highway driving while still maintaining good cross country speed.

Not to 'toot my own horn,' but I've been collecting 'lessons learned' in a FAQ. Mostly 'low hanging fruit,' not a bad place to double check.

Bob Wilson

 

Not to sound like a know-it-all, but he could make his own gas bladder out of some rubber, probably best to find some round rubber one online, possibly incase it in a medal box, and then just tap into the gas line on the Prius. I'm talking about the line to the tank, not the one to the engine. You'd need a valve, so you don't ruin the Prius's gas tank, that could be triggered via a button from the drivers seat. There would be lots of work involved and a voiding of any warranty on the car.

All in all it's not worth it just so you don't have to fill up as often.

Didn't even mention that the spare tank won't have all the safety features of the original tank. So something bad could happen and you wouldn't even know.

 

I used to have a van with a second add-on fuel tank. There was a switch on the dash so you could choose between them. I believe that each one had its own pump and what you were doing was deciding which one got power. I think each one had its own gauge too. You may need a second fill pipe also. You would need a "Y" fitting so either one could send gas to the engine. What I see as being the hard part is finding a place on the outside of the vehicle where there is physically room to place a tank. I wouldn't be wild about having a tank inside the car, even in the trunk.

 

Is your employer reimbursing your fuel costs?

If so, then perhaps you should re-think your use of the Prius and consider a different vehicle. You already carry 120lbs of stuff, which is almost equivalent to another person.

The Prius fuel tank just isn't designed for long-range driving like you do, and changing it is a huge job.

PS: Your auto insurance company will hate anything that changes the factory security of the fuel system, and you may fail state pollution requirements.

 

<div class='quotetop'>QUOTE(faith2walk @ Apr 21 2007, 07:58 PM) [snapback]427582[/snapback]</div>

Not a good idea. <_<
Safety , polution & warranty issues. Suggest planning ahead and fill up as soon as you get to a gas station.
Any mod in the fuel system is at best a risky undertaking.

 

Actually, when I take a road trip I need to stop to use the rest room more often than I need gas. Figuring 8 usable gallons per fill-up, at highway driving, that's about 400 miles. And at 65 mph that's 6 hours of driving. I certainly cannot drive for 6 hours without a pit stop. Even at 75 mph, that's 4 1/2 hours of driving at 42 mpg.

I generally average two to three pit stops per fill-up. At the very least, I need to stand up and walk around for 5 minutes after 2 or 3 hours of driving!

 

Any chance of swapping out the standard gas tank with the European version that does not have the bladder? The tank is supposed to hold 12 gallons, but it seems noone can get anywhere close to that much in their tank. There is no requirement for the bladder anyway--I believe the Prius is the only car that has it.

 

<div class='quotetop'>QUOTE(Per @ Apr 23 2007, 08:24 AM) [snapback]428337[/snapback]</div>

The US PRIUS has the bladder and associated tank components to improve the gas vapor handling. As Daniel said, driver’s bladder needs “servicing†much more often than the PRIUS.

 

We've driven on more than a couple occasions from our southern CA home to our MT home (1,250 miles) and we only have to stop 2X for gas. Getting between 500 - 600 miles per tank allows us to pick a station any where within a 100 miles, easily. So where's the need for more gallons?

 

<div class='quotetop'>QUOTE(hill @ Apr 23 2007, 12:35 PM) [snapback]428399[/snapback]</div>

My thoughts exactly.

After an hour or so on the road, I'm looking to stop to get out and walk around, take care of business, etc. The range on a Prius gas tank has to be one of the best available, and to me, there are plenty of reasons to stop before the gas gets low. I'd probably do 2 rest stops to every gas stop, if not more.

Harry

 

check out the details and pics of the fuel tank and bladder. we posted it to help folks get a better understanding of how it works.

http://priuschat.com/index.php?showtopic=31545