Running out of gas on purpose

I'll try to be honest and frank.

1) You can do this to your car, and likely nothing will go horribly wrong or any permanent damage will be done.

2) There is no guarantee that you will be able to reproduce your results, due to the nature of the fuel bladder.

3) It is exceedingly difficult, from what I've read, to get gas into a Prius using a gas can.

4) Honestly and Frankly, you would be foolish to do this. There is a lot of data from people who have posted on this site about running out of gas. While they may not take as exact a measurement as you might, there is nothing in the literature here to indicate that if once your light blinks that you will get X miles or have X gallons of gas left.

 

My advice is to carry 4 gallons. No guarantee the car will start up when you add just 1 gallon.

 

Theres been a report on pc of at least one person's HV battery dieing shortly after running out of gas. The warranty was voided and as far as I remember, the guy had to pay out of pocket because the dealer was able to determine user error (error code was set when the car runs out of gas I believe).

 

when the car runs out, pull over immediately. Do not drain the battery. The car uses the hybrid battery to turn the engine. it takes a lot of electricity if there is a lag between you running out and the fuel entering the engine again.

if you drive on electricity, you may run the battery too low to start.

keep in mind. electric motors are good at draining and killing batteries. This isn't your normal 12v starter motor. It's a 500V AC mechanical beast. Keep an eye on your state of charge or you may end up needed a new 4k dollar battery.

 

Here's an idea,

Get low on gas, at least until the gas low light illuminates, then pre-plan it so you are now simply performing dog-track runs around two or three blocks where there are a few gas stations.
If the engine dies, no problem, simply continue on to the next gas station, where you can fill it up (checking the fill level too).

Only don't do this during rush hour.


ZC1

 

Other posters have said bits and pieces of this, but let me put it in one place:

1) Carry at least three gallons of gas. The Prius doesn't notice that you have added gas until you get about three gallons into the tank. That doesn't mean it won't start with less, but you will have a dash full of warning lights until you get to the gas station and add more.

2) After you run out, pull over as soon as it is safe to do so. Driving on the HV battery is not good.

3) The gas gauge on the Prius is a bit fickle. I wouldn't trust anything that you learn from this experience. Pushing your Prius after the gas gauge gets low is just asking for trouble. I always fill at or before one pip on the gas gauge. On the highway I start thinking about gas when I get down to two pips. I'm not in a panic at two pips, but I know I'll need gas when it is convenient. At one pip I'm going to buy gas at the next station. When the last pip is flashing I may carjack someone to get gas.

Tom

 

i have another idea...dont do it with my prius!!!:bowl:

 

I've run out of gas in my 2006 prius at least 4 times, not really on purpose. I have to agree you cannot say "when light blinks you can go x far". I've ran out in as little as 11 miles after the light started blinking, and have made it as high as 45 miles after the light started blinking. That was the first time I ran out, maybe a week after I bought the car. At the time I assumed when it said I was averaging 45mpg it was close, and combined with the 11 gal fuel tank I'd run out somewhere close to 490 miles; I made it to 445. I now try to fill up as soon as the light starts blinking, though occasionally I find myself not planning correctly and end up going around 25 miles on the blinking light. There was a time I knew I could get at least 35-40 mile, but then that 11 mile run-out after the blinking light happened; incidentally I had just returned from Cleveland to Philly in January, maybe that had something to do with it.
BTW, I now carry a 1gal gas can which I bought after running out of gas the first time. I have not had any problems putting gas in the prius using it.

 

Dude,

Your Asperger's is showing!

I haven't had issues with the bladder noticeably changing the fuel tank capacity. I have had one issue where, I think, the car did not properly set itself up for refueling at shutdown.

The cutoff point varies from fuel pump to fuel pump. So, you will not get "the quoted 11.9 gallons" in all probability anyway.

I don't see the value in this experiment. Unless you are in an area with gas stations very far apart.

 

Fill-up before long trips in the desert? Just my 2 cents :canada:as from what I can tell you pretty well made up your mind to do this experiment and try to "discredit" any prior advice.

 

I ran my 03 Prius out of gas over two dozen times as part of my fuel studies. I used a one gallon, spare can with the next sample to test.

My experience:

• Over two dozen starts after adding one gallon
• No priming, the in-tank, fuel pump does all the work
• Traction battery supplies the ICE starting power
• The 12V battery runs the computers and does not start engine
• After adding 1 gallon, the fuel tank will not accept 11.9 gallons(1)
• Cutoff is when fuel backs up the filler tube(2)

Now for the implied questions:

1. The unusable fuel in the tank ranges from about .5-.7 gallons and should not be confused with the "flash" warning tank level.
2. Overfilling the tank pours gasoline into the vapor space around the bladder and this poisons the tank emissions control system. The car throws a master error code. Others have reported the car becomes unusable until the tank is replaced, an expense in excess of ~$1k.
3. The "flashing" low fuel level ranges from 0.8-2.5 gallons, a low of ~40 miles and a high of ~130 miles but the average is ~65 miles. I make sure the spare can is in the car once "flashing" begins.
4. When the car runs out of gas, use the battery to park in a safe place, NOW (within less than a fraction of a mile.)
5. Roadside traction battery recharging begins with a tow to a Toyota dealership followed by a wait of a week or so for the special charger to be shipped there. None of these costs are covered by any warranty.

GOOD LUCK!
Bob Wilson

 

Read the threads.. Pardon my being a bit BLUNT!!

Why would anyone want to purposely run their vehicle out of gas?.

FOR SOMEONE WHO APPEARS TO BE A DETAILED INDIVIDUAL, IT SOUNDS REAL DUMB TO ME THAT YOU WOULD WANT TO RISK THE WARRANTY FOR YOUR VEHICLE JUST TO GO A FEW EXTRA MILES..

Real Simple - When you get to 2 PIP's FILL HER UP!!!!

 

1. To empty the tank as part of gasoline studies.
2. To eliminate fear, uncertainty and doubt.
3. Less inaccurate fuel gauge

The last one, fuel gauge accuracy, is harder to quantify. The first time I ran out of gas, I ran 130 miles on the "flash" low fuel warning. I had started to wonder if someone was sneaking in some extra fuel. But after that first time, the average distance on "flash" has been around 65 miles. Running out of gas the 'first time' is difficult to replicate.

Bob Wilson

 

My suggestion is always fill up at 2 bars or more and never worry how far you can go on a flashing low fuel warning.

However it is your car so do as you please but if your battery fails just get a new one quietly without making a fuss, I don't need potential future buyers of my Prius reading about your battery failure. Of course battery failure may never occur but if it does ... shut up about it, no one wants to know.

 

Originally Posted by rkskeet
Why would anyone want to purposely run their vehicle out of gas?

4. To unload their wallet

 

Every vehicle I have ever owned or driven, I have topped off at 1/2 tank, no lower than 1/4 if caught between stations. I'm still unsure why Prius drivers appear to routinely run out of gas

Wonder what happens to that electric in-tank fuel pump when it runs dry and starts to cook itself?

 

Who told you this? It is so not true. I add fuel all the time to my Prius this way, when I don't have time to stop at the gas station I take lawn mower fuel from a can in my garage.


But running out of gas is not good for fuel injectors.