Do I need to run out of gas again to see if the tank really holds 11.9 gallons?

[CarlsbadKiter]

I ran out of gas last week in the Prius with 468 miles on the tank and getting a computer average of 46 miles per gallon.

It says the gas tank holds 11.9 gallons so figured I could go well over 500 miles on the tank easy. I was on the last bar, which was blinking when I ran out. When I filled it up, only 10.95 gallons went in (without over filling), so was a bit perplexed on two accounts—tank size and accuracy of mpg computer. If calculated on the tank fill-up, I was getting 43 miles per gallon. Apparently that computer readout resets automatically every 2.6 gallons. Still wondering about the tank size so may have to run out of gas to try and see if I can squeeze in 11.9 gallons. When I filled the tank, I was on level pavement and the temperature was around 70 degrees.

Do I need to run out of gas again to see if the tank really holds 11.9 gallons?

[Mystery Squid]

<div class='quotetop'>QUOTE(CarlsbadKiter @ Aug 17 2006, 12:57 PM) [snapback]304717[/snapback]</div>

I ran out of gas last week in the Prius with 468 miles on the tank and getting a computer average of 46 miles per gallon.

It says the gas tank holds 11.9 gallons so figured I could go well over 500 miles on the tank easy. I was on the last bar, which was blinking when I ran out. When I filled it up, only 10.95 gallons went in (without over filling), so was a bit perplexed on two accounts—tank size and accuracy of mpg computer. If calculated on the tank fill-up, I was getting 43 miles per gallon. Apparently that computer readout resets automatically every 2.6 gallons. Still wondering about the tank size so may have to run out of gas to try and see if I can squeeze in 11.9 gallons. When I filled the tank, I was on level pavement and the temperature was around 70 degrees.

Do I need to run out of gas again to see if the tank really holds 11.9 gallons?

[/b]

This is sort of a loaded question... I've managed to cram in as much as 12.5 gallons, basically, right until some gas spilled out. I've got a pic. on here somewhere of the pump showing 11.6 gallons... doesn't really answer your question, but I hope it gives you a perspective nonetheless...

[HeyKB]

<div class='quotetop'>QUOTE(CarlsbadKiter @ Aug 17 2006, 12:57 PM) [snapback]304717[/snapback]</div>

Do I need to run out of gas again to see if the tank really holds 11.9 gallons?

[/b]

Well, you can if you want, I suppose. But I wouldn't.

The fuel tank has a bladder which expands and contracts. So the tank almost never holds exactly 11.9 gallons.

There are actually dozens of posts here about running out of gas and the consensus is:
When the car says it's low on gas, fill it up!

Take that blinking dot on the fuel gauge seriously. Or do like we do and just fill up when it's convenient once you're down to a couple of dots.

[daronspicher]

My biggest fillup was 11.24 gallons. I have never run out, or even driven more than about 5 miles on the blinking dot.

I guess if you need to know if the tank holds 11.9, you may have to run it out. I don't really need to know, so my best is 11.24.

[Presto]

The tank is able to hold 11.9 Gal, but if you only fill up it till it clicks, you won't be at the capacity. I can usually get another gallon to 1.5 gallons of fuel into the car after it clicks.

I've gone 1001km at 4.5L/100km. So the capacity is definitely there.

[rufaro]

For the joys of having a bladder in your gas tank, see this google search results page, searching only PriusChat and using the words "gas" and "bladder."

And I can generally get two or more extra gallons in my tank after the pump clicks off.

[Rancid13]

<div class='quotetop'>QUOTE(CarlsbadKiter @ Aug 17 2006, 09:57 AM) [snapback]304717[/snapback]</div>

Do I need to run out of gas again to see if the tank really holds 11.9 gallons?

[/b]

One shouldn't run out of gas in any car, the Prius included. Especially not in order to prove a point to oneself or others, such as being able to put xx.x gallons into the tank on a fuel-up. Otherwise you risk permanently damaging the car and/or its hybrid components (per the manual).

[galaxee]

when the car says you need to add fuel, it's best to believe the car rather than decide for yourself how much gas is left in there.

[richard schumacher]

CbK, forget your experience with past cars. Because of the tank bladder you will never know exactly how much gas is in the tank, until the past pip starts flashing. Then you can be very confident that you are about to run out. (The MPG display is accurate because it counts each opening of a fuel injector; it does not measure changes in the fuel level in the tank.)

[RichBoy]

1 pip...fill up. flashing pip..fill up. remember, 99.99% of running out of gas incidents are caused by a defect in the nut behind wheel.