[WARNING] Running out of gas (Gen III)

What you are missing is 'knowledge'. Bob has done the 'out-of-gas' scenerio all the way back - when he took possession of his brand new Gen I , so that those who are so slow to let "out-of-gas" happen accidently will know what to expect, other than being stuck, out of gas. Some want to know. Will the car restart with a half gallon? ... 1 gallon? 2 gallons? ... will the battery be damaged? These are the nuggets we tinkerers pass on to others. I think the last nugget to be experienced is what happens to the PiP, when your gas runs dry, and you're on your last mile or two of EV. Will the PiP go into a turtle mode the way many EV's do? Or will it respond like the standard Gen III - not letting you even enter EV mode w/out gas. Or, if you've just switched to EV as you're sputtering out of gas, will you be able to remain in EV? Enquiring minds want to know. If you don't want to know - that's ok too.

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I guess I don't want to know (at least not first hand ), and I got the research part at the beginning of the thread, and think it's cool, but there are *lots* of posts about people's own experiences running out of gas. There are so many, I figured there had to be some "logical" reason that people are running their tanks dry.
I just didn't want to be the only guy who wasn't told... you know, the guy walking around with the sign taped to his back reading, "Don't fill my tank!" that everybody laughs at, but nobody will tell him about the sign.

So where is that &^%$in mirror???

Why should condensation be an extra concern with ethanol? Isn't filling up with E10 roughly equivalent to putting more than a gallon of gas line drier in the tank?

The only moisture problem I've heard with E10 was when it was first introduced locally, by government mandate. It soaked up and flushed through years of collected moisture in the fuel distribution and storage supply chain, all at once. After that, moisture couldn't collect enough to be a problem.

Your 1/2 tank rule, applied to my last non-hybrid, would cost me several dollars per refill on one of my regular trips. It wouldn't buy me any real peace of mind (math is easy for some of us), only permission to shut off the thinking cap.

That trip is 400 miles each way, plus an extra 20 miles or so during the stay at the other end. That old car goes the 330 miles between affordable fuel stops, and has comfortable safety margin (for me, not for you) even when lousy conditions cause the fuel needle to drop below E. A surprising amount of its fuel capacity is below that mark.

However, its range to the 1/2 tank mark is only 145 miles. Your half tank rule would demand refills at 146 miles (touri$t trap prices$) and 285 miles (al$o expen$sive, and the location of my long ago price gouging experience in a short fuel range car). The half tank rule would have me either running 82% of the trip on overpriced fuel, or making some extra stops for partial refills to get that overpriced fraction down to a mere 47%.

By better characterizing its fuel range, I can get that overpriced fuel fraction down to 0% and still be comfortable.

My first car had much shorter range, and negative reserve margin to E (i.e. it went dry above that mark). In theory, on some journeys, it could be above 1/2 at the 'next gas xx miles' signs and still not make it. So I paid higher average fuel prices, learned fuel planning, and made sure future cars had better range.

Old planning lessons die hard.

Nearly all of those are 'uncontrolled'. Engineers tend to prefer the better information of controlled experiments, when practical.

i have done this with almost every car i had and not quite sure why. i think its for the thrill of getting stuck, kinda like gambling. the more i think about it.... i think, my real reason is to wait till i can get to my fav gas station and being lazy. i can get away with driving from oc to la with the gas blinks, then go to work tomorrow with out pumping gas. esp helpful when your late for a party then tired while going home(which happens often).

I did this just because I was trying to get down so I could take advantage of a 25 cent code and I was running around helping my son in moving. I had never taken the car down to 0 mpg but the 4 or so times I had taken down to 50 miles i rarely got more than 10 gallons. The meter was flashing the whole time and most of the people that were in my car (my nephew told everyone i was running on empty). I got kinda nervous and when I finally did fill up, I took just a little over 10 gallons (i topped it off...)

I do want to warn people that I usually do get gas at a 1/4 tank so that probably has some bearing to the extra miles...

Hi,

I first started running out of gas in our 2003 Prius as part of my gasoline studies. I would carry a one-gallon, spare can of the next gas sample and then run the car out of gas. Each time, we got a dash full of lights and I used the traction battery to find a safe place to park and add the spare gallon. I've done this over three dozen times and will be doing it again after I put in the E85 kit. But things are different with the ZVW30.

The ZVW30 does NOT give an overt signal that the last of the gas is burned. However, the power flow arrows go away on the energy display. This is your only indication that you are now on traction battery power.

Personally, I believe having an overt warning is a valuable safety feature that Toyota should improve upon. Perhaps even a warning light that says, "No gas, drive slow, park now" but apparently Toyota does not share my thinking. They would rather deal with the current rumors of bad brakes and run-away acceleration. After all, they deserve the right to run the experiment.

Every year about 5-10 pedestrians die on the side of the highway with a spare gasoline can in their hands. When that turns out to be a Prius owner, I will attach the article to a letter sent to Toyota and copy to the NHTSA . . . not that it will do any good. But at least I will not have sat on my hands!

Bob Wilson

Dri-gas is methanol, not ethanol. Methanol has it's own problems, but it is good at dissolving water in gasoline. While it is true that today blenders put a corrosion inhibitor into all E10 blends, it's effectiveness is limited. It is also true that auto manufacturers are cognizant of the problem and had greatly upgraded the quality of materials used in fuel systems. However, I am not willing to put all my faith in remedial measures. Keeping water out of the fuel system is the best way to avoid problems. Michigan has both high humidity and daily temperature changes - thus the advantage to reducing air volume in the tank.

Did I not make it clear that one of the factors I was taking into account was the increased time between fill ups now that I'm driving my Prius. Thus your comments about your old non-hybrid and taking long trips are not responsive to my question. On a trip, when you are burning through a tank in a single day, or even multiple tanks there is no opportunity for condensation to form. I am not obsessive-compulsive, rules are guidance not laws.
On a long trip I still follow the 1/2 tank rule - but the rule is my bladder - I stop whenever my bladder is 1/2 full.

Not old planning - careful thought.

Iso-HEET and some other gas line dryers are isopropyl alcohol. Because methyl, ethyl, and isopropyl alcohols are all miscible with water, do they all not have similar effects with moisture in the fuel tank?

I have generally divorced pit stops from fuel stops. The cheapest fuel often comes with no restrooms, or hideous restrooms, and doesn't fit the travel companion's bladder schedule. The most scenic and/or pleasant restrooms don't have fuel available.

Thank you, Bob, for being the point man on Prius knowledge.

I think we've all learned something here. Some people are gamblers, some aren't, and some force their will upon the world regardless of the risk.

Me, I'll just fill up when I start feeling queasy. If I need to go a precise, long mileage on a tank, I'll buy a bigger tank.

Maybe it's because I grew up in the west, where sometimes there were long miles between gas stations, but I tend to gas up fairly frequently when on long trips. As my dad used to say, "It costs the same in the long run whether you add it a little at a time or all at once."

For daily commuting, I go by gas prices, because over time there are differences. If prices are rising, I buy more often to get gas while it's cheaper. If prices are falling, I buy less often so I get lower prices.

No. With ethanol you get phase separation at relatively low volumes of water. And adding either methanol or isopropyl alcohol to ethanol bearing fuels that have undergone phase separation has a number of bad effects. If you ever do get phase separation in ethanol/gasoline fuels, the only wise course of action is to completely drain the fuel system.
It is suitable to use a stabilizer like Sta-Bil, but that would certainly negate any savings from searching for cheap gas.

Yes, I realize that our fuel systems are far better sealed than that jar, but,again, that's why I made the point of going weeks between fuel-ups. Fuel system repairs are expensive, buying gas every week is not.