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Discussion Starter #1 (Edited)
I'm in LOW fuel and would like to run the tank all the way down. But I'll be driving on freeways.

How fast can I go when out of fuel and displaying "Out of Fuel/Engine Unavailable"?

There is no range problem getting to a gas station on EV. I just don't want to carry much gas around and want it all to be fresh.

[Edit: Oops - just realized that I will be in Out of Fuel mode, not PPR mode. Sorry.]
 

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think I stayed in MM mode to almost no gas - but was in 35 MPH area not freeway.

Sport mode I forgot to try.
 

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Just because you can do a thing, doesn't mean you should.
Running the tank absolutely dry is a bad idea for any number of reasons including damaging your fuel pump.
 

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I'm not sure on the gen2. On the gen1 the pump shuts off while there is still fuel in the tank/line. So I don't believe it will damage the pump.
It would mostly just ding and annoy the piss out of you for not putting fuel in it, because 9/10ths of the car and the engineering want to to know that it is a GM vehicle that uses gasoline, not an EV. It seems to hold the gas engine in a much more regard as a backup, and when you purposely ditch the backup it wants you to know how terrible it is by gimping you and itself.
 

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Found this thread in the forum archive: https://gm-volt.com/forum/archive/index.php/t-223249.html

See response from canehdian: This behavior occurs on all cases where the gas runs out, regardless of the charge level of the battery. To rectify the situation the user should add 0.1 gallons of gas to the gas tank. After that the car is happy to proceed with full acceleration again, as long as there is enough charge in the battery.

Somewhat annoying thing when you know you can get to work and back with the fully charged battery and you really don't want to stop for half an hour for the fill up in the morning.

It has nothing to do with the fuel level. Any failure of the engine (which includes running out of fuel, but is not exclusive to) will result in
ENGINE NOT AVAILABLE
PROPULSION POWER REDUCED

Mine failed with a mostly full battery while EMM was running (infant mortality).
I just drove home on PPR and made an appt with dealer.
It is noticeably sluggish, with a power limit of half the normal (55kW).

I believe driving on the freeway will be possible but on-ramp acceleration will be very slow, potentially unsafe. If you feel the need to burn off all of the old fuel why not do this while driving other than on of the freeway.
 

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Discussion Starter #6
I ran out today just before getting on the SF - Oakland Bay Bridge. It ran just fine except that the acceleration was limited. But it got up to 60 mph with no problem - just took longer.

I drove 25 miles to my home gas station and put in 1.5 gallons. That should do me for another year. (Before this FMM, the last time the ICE turned on, other than EMM, was December 31, 2016.)

Running the tank absolutely dry is a bad idea for any number of reasons including damaging your fuel pump.
The Volt manual says "If the vehicle runs out of fuel, or the engine will not start due to a malfunction, the vehicle can continue to be driven in Electric Mode until the current charge is depleted."

If there were any reason not to run the tank dry, I trust GM would have put a caution in the manual. And considering how smart the Volt is, it probably would not have used the last drop in the tank.

In fact, maybe it didn't. No way to tell, because after it gets below a gallon, the dash gas range reads LOW and the OBDII shows 0 gas.
 

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Someone driving a Gen 2 Volt with plenty of power in the battery and wanting to run out of gas is either experiencing an FMM episode (when the engine runs and you can’t use the battery until you do something about the "old" gas) or is trying to empty the tank by using Hold Mode.

Sounds like you’re using Hold Mode to use up your remaining existing gas, and want to use it all up before you add even a small amount more in order to maximize the delay until the next FMM might occur.

Note that the gas range estimate, when it switches from a number to Low Fuel (with ~1.5 gallons of gas remaining), can be misleading. If you haven’t used gas much recently, the estimate is likely a low number, reflecting "cold engine" gas mileage. Once you choose to run the engine until the gas is gone, the distance you may drive on the remaining gas may significantly exceed the "cold engine" gas range shown just before Low Fuel appeared.

Yes, when you run out of gas, you’ll experience a Propulsion Power Reduced episode until you get more gas, but will be able to use all available battery power. If the driving conditions at that moment require only a moderate power demand (e.g., you are cruising smoothly on the freeway), it is possible the primary issue you will encounter is less responsive acceleration.

Be aware that if you run out of gas (my preferred method of ending an FMM, and I’ve experienced 3 of them in 6+ years in my 2012 Volt), once you do add gas, the engine performs a self test to confirm all is in working order before the car returns to normal operations. The Gen 2 manual has this to say regarding Out of Fuel/Engine Unavailable:

"If the vehicle runs out of fuel, or the engine will not start due to a malfunction, the vehicle can continue to be driven in Electric Mode until the current charge is depleted. The vehicle will have less responsive acceleration. DIC messages indicate reduced propulsion power, that the engine is not available, and the need for fuel or service. Once the vehicle is refueled, or the malfunction is corrected, the engine will start the next time the vehicle is turned on to perform a self test, and DIC messages will not be displayed. Once the engine starts successfully, normal operation will continue in either Electric or Extended Range Mode. The engine may stop running after the self test is completed, based on the current mode of operation."
 

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Discussion Starter #8
Sounds like you’re using Hold Mode to use up your remaining existing gas, and want to use it all up before you add even a small amount more in order to maximize the delay until the next FMM might occur.
Thanks for the reply. Yes, except that it was in FMM, not Hold Mode.

Be aware that if you run out of gas (my preferred method of ending an FMM, and I’ve experienced 3 of them in 6+ years in my 2012 Volt), once you do add gas, the engine performs a self test to confirm all is in working order before the car returns to normal operations.
It did that, but for less than a minute, and indicated that it was running on battery nevertheless.
 

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Fuel pumps are cooled and lubricated by the fuel. If there is no fuel in the tank, the pumps will be running dry. The Volt will attempt to start the ICE for 15 seconds, during which your fuel pumps will be experiencing greatly accelerated wear. Would you run your engine for 15 seconds without oil in it?

Running a Volt out of gas is a bad idea for the same reasons running an ICE car out of gas is. It's bad for the car. Just because you can keep going on battery afterwards (at reduced power, which could be dangerous) in the Volt is not an invitation to do so. The Volt is not meant to be driven without gas. It's a hybrid. If you need to use gas so infrequently that you're worried about using up every last drop to delay FMM, why'd you not buy a Bolt or other fully electric car?
 

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The consensus on the forum is that the modern fuel pumps will not attempt to operate if there is no fuel.
 

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Discussion Starter #14
The Volt is not meant to be driven without gas. It's a hybrid.
Yes, the Volt is meant to be driven without gas. Not as a usual thing, but I only did it once in three years.

As has been mentioned twice in this thread already, the Volt manual says "If the vehicle runs out of fuel, or the engine will not start due to a malfunction, the vehicle can continue to be driven in Electric Mode until the current charge is depleted." If there were a reason not to drive it like that, GM would have put a caution in the manual.

If you need to use gas so infrequently that you're worried about using up every last drop to delay FMM, why'd you not buy a Bolt or other fully electric car?
Because I bought the Volt a year before the Bolt became available.

Because I wanted the option to take the Volt on occasional long trips.

Because I was willing to pay for the ICE and drag it around in return for never, ever having to even think about running out of charge and being stranded.
 

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If you need to use gas so infrequently that you're worried about using up every last drop to delay FMM, why'd you not buy a Bolt or other fully electric car?
Because I bought the Volt a year before the Bolt became available.

Because I wanted the option to take the Volt on occasional long trips.

Because I was willing to pay for the ICE and drag it around in return for never, ever having to even think about running out of charge and being stranded.
None of these explain why "every last drop" is important. If you're willing to carry around 300 lbs of ICE, why spend any time at all thinking about how to get rid of 10 lbs of gasoline?
 

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Discussion Starter #16
None of these explain why "every last drop" is important. If you're willing to carry around 300 lbs of ICE, why spend any time at all thinking about how to get rid of 10 lbs of gasoline?
Because some things are fun to optimize, and this was one of them.

Because I enjoyed optimizing my Miles per Tank and Miles Without Gas on Volt Stats, which required multiple doses of a few gallons at a time to put FMM off as long as possible. So this was my last swing at putting off the next FMM as long as possible. Force of habit.

Now go ahead - tell me I'm wrong to enjoy Volt Stats. (At least I don't enjoy telling other people how they should or shouldn't enjoy their Volt.)
 

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Fuel pumps are cooled and lubricated by the fuel. If there is no fuel in the tank, the pumps will be running dry. The Volt will attempt to start the ICE for 15 seconds, during which your fuel pumps will be experiencing greatly accelerated wear. Would you run your engine for 15 seconds without oil in it?

Running a Volt out of gas is a bad idea for the same reasons running an ICE car out of gas is. It's bad for the car. Just because you can keep going on battery afterwards (at reduced power, which could be dangerous) in the Volt is not an invitation to do so. The Volt is not meant to be driven without gas. It's a hybrid. If you need to use gas so infrequently that you're worried about using up every last drop to delay FMM, why'd you not buy a Bolt or other fully electric car?
With a Volt, the smaller motor serves as the gas engine’s "starter motor." The Volt’s computer turns the engine off when the car runs out of gas. The Volt has no "engine starter" button. If you turn the car off, you can then push the blue "start" button and start driving in Electric Mode, but the car won’t attempt to get the engine to turn over if there’s no fuel in the tank.

Why empty the tank before adding new gas if you use almost no gas? To keep the number of FMMs down to one per year instead of two or three or more.

If you empty the tank and add only the ~1.5 gallons minimum, and then don’t use that up within the next ~318 days (the small amount of gas left in the system after the engine stops because the tank is "empty" is actually enough to shorten the next FMM by ~47 days from the expected 12 months), if you then just put a minimum amount of "new" gas into the tank with the remaining "old" gas, the "old" gas remaining in the system forms a larger portion of the new whole, and the interval until the next FMM will shrink, perhaps down to 6 months or less.
 

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Although I have no data to support this I feel that 6 weeks is too long an interval to not start and run the Volt's gas engine. I will go a month and then start and warm my Volt's engine. I have a home standby generator that starts and runs for ~12 minutes every week. The generator is air cooled, has a 2-cylinder 4-cycle engine that and runs on natural gas. The generator owner's manual cautions against not exercising the generator at least every 30 days without deploying additional engine maintenance procedures.
 

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Discussion Starter #19
If you empty the tank and add only the ~1.5 gallons minimum, and then don’t use that up within the next ~318 days (the small amount of gas left in the system after the engine stops because the tank is "empty" is actually enough to shorten the next FMM by ~47 days from the expected 12 months) ...
So are you / can you confirm my suspicion that when the Volt reports "Out of Fuel", there is still a little gas in the tank?

If that is so, then the fuel pump can't run dry.
 

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"So are you / can you confirm my suspicion that when the Volt reports "Out of Fuel", there is still a little gas in the tank?"

so to test this do I try to run out of gas going up a big hill or down said hill ?
 
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