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Discussion Starter · #1 ·
I commute 110 miles every day (not my choice :cry: )
I was driving my 2000 Taurus (200 HP 24 valve) and getting from 26 to 29 MPG, at 69 mph on CC. With an 18 gallon tank I can comfortable get gas every 3 days, 4 if I strech it. I figure that I spend at least 11 hours a year sitting at a gas station, waiting to refill (if it only takes 10 minutes average).

So I decided to get a Prius.
After a 9 month wait, I got a '04, gold, pkg#9.

My hope is that I could refill every 5 days, saving 5 hours a year.
So I studied the mileage that I was really getting for 5000 miles (51 mpg at 69 mph on CC), before trying to strech it. According to those numbers I should be able to get 609 miles to empty, 591 with a 3% error.

Well, the other day, with the display claiming a 51.2 average, the car run out of gas after 530 miles :!: :?

I was on the NJ turnpike, and the ICE shut off in a perfectly flat stretch.
I was able to go in EV mode for a couple of miles on the shoulder until that quit too. (The display was telling me that I needed gas.)

I got my cell and was looking for the AAA number, when I decided to try to start the car. Guess what! The ICE started, all warning lights went off, it drove normally and I made it to a gas station... phew :!: :)

Why did the car think that is was out of gas :?:

I know that when you are going up or down a hill and have little gas in the tank, the pump might suck air and stall. This was not the case...

Does anybody know if the Prius intake is in the center, front or back of the gas tank :?: (In other words, you could stall by going up or down a hill.)

If you run out of gas and then run down the battery, how can you start the car :?:
(The user's manual explains how to jump start the 12 volt battery. Is that what you will need to do in this case?)

What is the 12 volt battery used for :?: I was told that it powers accessories. Is it also used to start the ICE if the big battery is down?

I read in this forum that the US version has a bladder in the gas tank.
What makes the bladder descend against the gas :?: Just gravity, or is it pressurized :?:
The bladder must reduce the amount of gas that fits int the tank, unless it is extremely thin.

What is the fuel capacity of models without the bladder? Can I remove it to gain fuel capacity?

· Registered
478 Posts
The car very likely didn't try to restart, since it was well aware of the situation it was in. (A built-in safety precaution.) A little bit of gas settling afterward and the attempt while not in motion, is probably what allowed it to start later.

As for starting with an very deeply-discharged battery-pack, you've got other problems to worry about. The stress likely shortened it's life. That's why it is so important to get out of harm's way, then stop. Don't proceed any further.

Sorry you ran out of gas. But with the upcoming winter, everyone needs to keep in mind that pushing it isn't a good idea. Besides the battery-pack concern, the tank itself reduces in capacity. The cold causes the bladder to contact.

And no, you likely cannot remove the bladder (which signficantly reduced evaporative emissions). Even if the pump still worked, the gauge probably wouldn't. A replacement would be needed instead.

I recommend using the 9-gallon tolerance, just matching distance to MPG shown on the Multi-Display to indicate when to refill...

40 MPG = 360 miles
41 MPG = 369 miles
42 MPG = 378 miles
43 MPG = 387 miles
44 MPG = 396 miles
45 MPG = 405 miles
46 MPG = 414 miles
47 MPG = 423 miles
48 MPG = 432 miles
49 MPG = 441 miles
50 MPG = 450 miles
51 MPG = 459 miles
52 MPG = 468 miles
53 MPG = 477 miles
54 MPG = 486 miles
55 MPG = 495 miles

I also point out that gas pumps themselves can be a pain. Varying a 1/2 gallon from one to another is fairly common. So that interferes with expectations too.

· Registered
858 Posts
Thanks, John, for answering the primary questions. Here are answers to some of the other questions:

Running out of gas and running down the HV battery will not cause you to need to jump the 12V battery. However, the Prius will no longer be charging the small 12V battery, so it may run down through lights, fans, and accessories in an hour or so if you fail to turn off the car.

There is no 12V starter motor, so the Prius cannot be started without the HV battery.

If you run out of gas and run down the HV battery, it still has a small amount of charge left which the Prius hoards. It won't let you use it to start until you get to a Toyota dealer's service department. They have a tool which can put the computers in a special emergency start mode. You should still have enough charge to try at least two or three more starts. They will verify gasoline has been placed in the tank before trying this (hopefully).

The bladder has been described as being like a waterbed mattress. So gravity causes it to descend against the gasoline (and a small vaccuum since the gas cap offers some resistance to air entering the tank). It is never stretched under normal use, though there are stories suggesting that it can be pressurized if you fill it too full, causing gas to squirt back out when you remove the pump nozzle.

· Registered
8 Posts
Discussion Starter · #5 ·
Thanks you guys for the information :!:

Now I know not to try to get over 500 miles...

The gas gauge was at the last block, blinking. I put about 50 miles since it started blinking. When I refilled it, it took about 11 gallons (I wrote it down, but I don't have it with me now...)
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