Running X5 45e with no gas in the tank?

aMIC · 11-13-2022, 12:33 AM

Side question: would be possible to run the BMW 45e without gas at all but with still same charge in the battery? Like for example when we run out of gas and would like to continue to run on battery until find a gas station

eelnoraa · 11-13-2022, 12:48 AM

Quote:

Originally Posted by aMIC

Side question: would be possible to run the BMW 45e without gas at all but with still same charge in the battery? Like for example when we run out of gas and would like to continue to run on battery until find a gas station

I don’t see why it is not possible but i haven’t tried. And I don’t intend to try. Running tank to empty is bad for fuel pump. How do you get to they situation? Like charge batter full, then drive in sport model only until tank empty?

jad03060 · 11-13-2022, 12:54 AM

First, you don't really want to actually run the tank down all that low as you can damage the fuel pump because it is in the tank and both cooled and lubricated by the fuel. But assuming you didn't damage that, you could keep going with the EV motor. You'd want to probably put it in EV mode versus hybrid so there's less chance it would want to start the motor if you pushed the accelerator too hard...it can still happen, but you have to mash it past the detent. In hybrid mode, it will try to start the motor much sooner and at a lower speed.

aMIC · 11-13-2022, 01:44 AM

Quote:

Originally Posted by eelnoraa

I don’t see why it was any possible but i haven’t tried. And I don’t intend to try. Running tank to empty is bad for fuel pump. How do you get to they situation? Like charge batter full, then drive in sport model only until tank empty?

Not yet :-) I didn't received yet my 45e and was curious what could happen if I ever run out of gas.

Other PHEV may have a limping (?) mode for this situation :

eelnoraa · 11-13-2022, 03:41 AM

Quote:

Originally Posted by jad03060

First, you don't really want to actually run the tank down all that low as you can damage the fuel pump because it is in the tank and both cooled and lubricated by the fuel. But assuming you didn't damage that, you could keep going with the EV motor. You'd want to probably put it in EV mode versus hybrid so there's less chance it would want to start the motor if you pushed the accelerator too hard...it can still happen, but you have to mash it past the detent. In hybrid mode, it will try to start the motor much sooner and at a lower speed.

I hate to be the one that always point out what actual is the issue vs what application note says.

In theory, yes, this is correct. But in reality, this is really not the issue. LPFP is driven by electric motor. When there is no liquid, the pump will free spin at a much higher rate, this is usually what cause the issue. However in reality, this isn't the issue either. When car is moving with low fuel, gasoline swash around in tank. LPFP will start sucking in air, but there are still enough gas in the fuel system, so no so called cooling/lubricant issue. The pump will spin fast when it encounter air pocket, then slow down there is gasoline. Engine will start
"choking". From chocking to engine no long can run, probably take 2-3 minutes. And even when engine cannot run, there is still quite some gasoline in the fuel system, just enough air pockets inside. Overall, the stress to the fuel pump is not bad. Running out of fuel a few time definitely won't damage fuel pump. LPFP is very simple and robust device. Just don't make a habits out of it.

volodp · 11-13-2022, 04:42 AM

Once it happened to me that my usual gas station was closed and I decided to keep going with the tank almost empty. I should have made it to the next station just fine but there was a detour so I've burned (practically) all my fuel and came to the station with my remaining electric range equaling total remaining range. And here's the message that I've got. But otherwise the car was running on electricity with engine off and no error messages for the last few kilometers.

nZtiZia · 11-13-2022, 08:35 AM

You'll get a warning of limited drive power if you let the fuel tank run empty. the ICE is completely offline so you're only running on Electric power. depending on your traffic situation, this can be very dangerous.

I let it run completely empty during my commute to work when I first got it to see what happens. my advice is don't let fuel run empty.

scungilio · 11-13-2022, 09:02 AM

Why would anyone even think of driving a PHEV with an empty gas tank. I guess there are those who will buy an $80,000 BMW and allow the 25 or 30 mile range on battery to limit their freedom. This makes no sense at all as in why not just buy a fully electrified ride that doesn't drag an engine along with all the other hardware around.

nZtiZia · 11-13-2022, 10:22 AM

Quote:

Originally Posted by scungilio

Why would anyone even think of driving a PHEV with an empty gas tank. I guess there are those who will buy an $80,000 BMW and allow the 25 or 30 mile range on battery to limit their freedom. This makes no sense at all as in why not just buy a fully electrified ride that doesn't drag an engine along with all the other hardware around.

there's nothing here in this thread giving the impression that folks would buy the 45e with the intent of running it as a pure EV. the OP put up a hypothetical situation and asked if there are repercussions in doing so. (I ran the fuel empty for testing purposes.)

scungilio · 11-13-2022, 10:34 AM

Quote:

Originally Posted by nZtiZia

there's nothing here in this thread giving the impression that folks would buy the 45e with the intent of running it as a pure EV. the OP put up a hypothetical situation and asked if there are repercussions in doing so. (I ran the fuel empty for testing purposes.)

That is not what I said. I asked why anyone would ever consider driving a vehicle with an empty gas tank. No one is going to ask this question if they had no intention of ever doing so.

nZtiZia · 11-13-2022, 11:12 AM

Quote:

Originally Posted by scungilio

That is not what I said. I asked why anyone would ever consider driving a vehicle with an empty gas tank. No one is going to ask this question if they had no intention of ever doing so.

aMIC hypothetical scenario doesn't portray intent, it portrays circumstance. "is it safe to run electric if i run out of fuel for a while until I can find a gas station?"

scungilio · 11-13-2022, 01:08 PM

Quote:

Originally Posted by nZtiZia

aMIC hypothetical scenario doesn't portray intent, it portrays circumstance. "is it safe to run electric off i run out of fuel for a while until I can find a gas station?"

I understand now, he is asking because he has no "intent" to do this.

volodp · 11-13-2022, 02:29 PM

I certainly wasn't doing this intentionally or for testing purposes. Just ran out of fuel while getting to the next gas station and while still having some battery charge left. So I thought I'd share what happens in that scenario. Nothing more, nothing less.

eelnoraa · 11-13-2022, 02:50 PM

Quote:

Originally Posted by volodp

I certainly wasn't doing this intentionally or for testing purposes. Just ran out of fuel while getting to the next gas station and while still having some battery charge left. So I thought I'd share what happens in that scenario. Nothing more, nothing less.

Thank you for sharing. It is always good to know what to expect in certain special scenarios. While not intended, but in a pinch, we need to go for the extra miles to get to the next station, it is good to know we can do it.

eelnoraa · 11-13-2022, 02:51 PM

Quote:

Originally Posted by nZtiZia

there's nothing here in this thread giving the impression that folks would buy the 45e with the intent of running it as a pure EV. the OP put up a hypothetical situation and asked if there are repercussions in doing so. (I ran the fuel empty for testing purposes.)

Also want to express my appreciation for your dedication as always. Take one for the team in the name of science. 😁👍

jad03060 · 11-13-2022, 06:24 PM

If you happen to be going up an incline...what fuel you may have may not be able to get to the pump, and then, it's spinning with no cooling or lubrication...not good for anything. There's a reason why the low fuel indication comes on...abide by it and seek fuel soon. It also puts a lot of stress on the engine if it's misfiring from lack of fuel.

ksavostin · 11-13-2022, 06:31 PM

I have been driving my 45e without gas for a few months this summer with no issue at all.
Pros - car feels a bit lighter and a bit quicker than when your gas tank is full.

Guy Fleegman · 11-14-2022, 08:10 AM

Quote:

Originally Posted by volodp

I certainly wasn't doing this intentionally or for testing purposes. Just ran out of fuel while getting to the next gas station and while still having some battery charge left. So I thought I'd share what happens in that scenario. Nothing more, nothing less.

This is a useful thread. I found myself on a lonely highway in Montana and when the estimated range got below 50 miles I started looking for fuel. Started to get a little nervous when two gas stations were closed and the range dropped below 20. I had about half the battery charge remaining so I figured in a pinch I could keep gliding for a few more miles. Maybe "hoped" is more accurate, since I wasn't certain whether the indicated range included the electric or was ICE only.

This is not something you want to have to learn on the fly in a remote area. Things worked out okay in this case but I won't cut it that close again.

scungilio · 11-14-2022, 08:41 AM

Quote:

Originally Posted by jad03060

If you happen to be going up an incline...what fuel you may have may not be able to get to the pump, and then, it's spinning with no cooling or lubrication...not good for anything. There's a reason why the low fuel indication comes on...abide by it and seek fuel soon. It also puts a lot of stress on the engine if it's misfiring from lack of fuel.

I would agree with all of this and half a tank of fuel in a 45e only weighs 50 lbs or less than 1% of a 5800 lb vehicle.
Experimentation is fine if that is what you are interested in doing but understand that driving around with no gas in the tank is a bad idea.

jad03060 · 11-14-2022, 05:32 PM

You can select range to empty that is either ICE only, or ICE plus EV, and view the EV range alone, at least in the app, and I think on the display in the vehicle. But, keep in mind, all of those estimates are based on you driving exactly as you had been for the past about 18-miles, or 30Km. Change your driving style, the value will slowly change, but if there's not much left, it can change fairly rapidly.

11-13-2022, 12:33 AM	#23
aMIC Private 31 Rep 78 Posts Drives: BMW 325 XIT , X5 45e Join Date: Nov 2022 Location: Bay Area, California iTrader: (0)	Side question: would be possible to run the BMW 45e without gas at all but with still same charge in the battery? Like for example when we run out of gas and would like to continue to run on battery until find a gas station
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11-13-2022, 12:54 AM	#25
jad03060 Major General 3242 Rep 6,942 Posts Drives: X5 45e Join Date: Aug 2018 Location: NH iTrader: (0)	First, you don't really want to actually run the tank down all that low as you can damage the fuel pump because it is in the tank and both cooled and lubricated by the fuel. But assuming you didn't damage that, you could keep going with the EV motor. You'd want to probably put it in EV mode versus hybrid so there's less chance it would want to start the motor if you pushed the accelerator too hard...it can still happen, but you have to mash it past the detent. In hybrid mode, it will try to start the motor much sooner and at a lower speed.
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11-13-2022, 04:42 AM	#28
volodp Second Lieutenant 200 Rep 225 Posts Drives: 2021 G05 45e, 2022 iX40 Join Date: Feb 2020 Location: Prague, Czech Republic iTrader: (0)	Once it happened to me that my usual gas station was closed and I decided to keep going with the tank almost empty. I should have made it to the next station just fine but there was a detour so I've burned (practically) all my fuel and came to the station with my remaining electric range equaling total remaining range. And here's the message that I've got. But otherwise the car was running on electricity with engine off and no error messages for the last few kilometers. Attached Images
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11-13-2022, 08:35 AM	#29
nZtiZia Major General 4753 Rep 8,864 Posts Drives: eVeRyOnE mAD! Join Date: Dec 2020 Location: neither here nor there... iTrader: (0) Garage List 2021 BMW X5 xDrive 45e [9.88]	You'll get a warning of limited drive power if you let the fuel tank run empty. the ICE is completely offline so you're only running on Electric power. depending on your traffic situation, this can be very dangerous. I let it run completely empty during my commute to work when I first got it to see what happens. my advice is don't let fuel run empty.
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11-13-2022, 09:02 AM	#30
scungilio Banned 166 Rep 335 Posts Drives: bmw x5 Join Date: Oct 2022 Location: SE iTrader: (0)	Why would anyone even think of driving a PHEV with an empty gas tank. I guess there are those who will buy an $80,000 BMW and allow the 25 or 30 mile range on battery to limit their freedom. This makes no sense at all as in why not just buy a fully electrified ride that doesn't drag an engine along with all the other hardware around. Last edited by scungilio; 11-13-2022 at 10:04 AM..
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11-13-2022, 02:29 PM	#35
volodp Second Lieutenant 200 Rep 225 Posts Drives: 2021 G05 45e, 2022 iX40 Join Date: Feb 2020 Location: Prague, Czech Republic iTrader: (0)	I certainly wasn't doing this intentionally or for testing purposes. Just ran out of fuel while getting to the next gas station and while still having some battery charge left. So I thought I'd share what happens in that scenario. Nothing more, nothing less.
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11-13-2022, 06:24 PM	#38
jad03060 Major General 3242 Rep 6,942 Posts Drives: X5 45e Join Date: Aug 2018 Location: NH iTrader: (0)	If you happen to be going up an incline...what fuel you may have may not be able to get to the pump, and then, it's spinning with no cooling or lubrication...not good for anything. There's a reason why the low fuel indication comes on...abide by it and seek fuel soon. It also puts a lot of stress on the engine if it's misfiring from lack of fuel.
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11-13-2022, 06:31 PM	#39
ksavostin First Lieutenant 128 Rep 305 Posts Drives: 2021 X5-45e Join Date: Aug 2020 Location: Anchorage, Alaska iTrader: (0)	I have been driving my 45e without gas for a few months this summer with no issue at all. Pros - car feels a bit lighter and a bit quicker than when your gas tank is full.
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11-14-2022, 05:32 PM	#42
jad03060 Major General 3242 Rep 6,942 Posts Drives: X5 45e Join Date: Aug 2018 Location: NH iTrader: (0)	You can select range to empty that is either ICE only, or ICE plus EV, and view the EV range alone, at least in the app, and I think on the display in the vehicle. But, keep in mind, all of those estimates are based on you driving exactly as you had been for the past about 18-miles, or 30Km. Change your driving style, the value will slowly change, but if there's not much left, it can change fairly rapidly.
	Appreciate 0 Quote