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Gas on Empty?

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Originally posted by: Munchies
Correct, I have torn done hundreds of engines, my own that I have run out of gas in many many times before an there has been no damage.
Nobody said it was going to damage the car.

I stated in my first post that thats what your fuel filter is for. 😛 No baddies are going to get into your engine through the fuel system.

I'm sure what you say about newer cars is true, but I have heard of cars where the pump relies on the fuel to cool it..

Probably older models, as you suggest.
Originally posted by: Munchies
Its going to not makea diff. Ever hear of wtaer injection on gas engines?
Condensation in the fuel tank is indeed a problem. Why do you think they sell all those de-ice/water-ers next to the carb/fuel injector cleaners? 😛
 
Eli is correct, nearly all cars with electric fuel pumps can do damage to the pump by running it repeatedly low on gas.....and I mean low enough to constantly uncover the pump and get air into it.
Edit: Don't believe me? Take a pump and power it up with nothing flowing through it and see how long it lasts.

1/4 tank generally isn't low enough to do that, much less 1/2 tank. But the theory is correct, running an electric pump w/out gas flowing through it WILL damage it if done enough. The gas DOES cool the pump.
Some cars are obviously more susceptible to this damage than others.

Oh, and the reason some pumps are mounted IN the tank is because the gas dampens the noise, not for cooling.

And yes, the pickup on ALL cars is in the bottom of the tank, so it's right down there sucking up whatever crud is on the bottom all the time, full or empty......that's why fuel pump pickups have a sock/filter on them, to avoid anything large enough to damage the pump; the fuel filter takes care of the rest.
 
Originally posted by: Eli

Its going to not makea diff. Ever hear of wtaer injection on gas engines?
Condensation in the fuel tank is indeed a problem. Why do you think they sell all those de-ice/water-ers next to the carb/fuel injector cleaners? 😛[/quote]
Don't think that's what he's talking about.
 
Originally posted by: Pacfanweb
Eli is correct, nearly all cars with electric fuel pumps can do damage to the pump by running it repeatedly low on gas.....and I mean low enough to constantly uncover the pump and get air into it.
Edit: Don't believe me? Take a pump and power it up with nothing flowing through it and see how long it lasts.

1/4 tank generally isn't low enough to do that, much less 1/2 tank. But the theory is correct, running an electric pump w/out gas flowing through it WILL damage it if done enough. The gas DOES cool the pump.
Some cars are obviously more susceptible to this damage than others.

Oh, and the reason some pumps are mounted IN the tank is because the gas dampens the noise, not for cooling.

And yes, the pickup on ALL cars is in the bottom of the tank, so it's right down there sucking up whatever crud is on the bottom all the time, full or empty......that's why fuel pump pickups have a sock/filter on them, to avoid anything large enough to damage the pump; the fuel filter takes care of the rest.

pwned
 
If you bleed your gas reserves dry and keep going until there's no fuel and start hearing a sputtering sound, you can either do 2 things:

1) keep trying to accelerate like a jack-ass and POSSIBLY mess up your engine(try it for yourself or take advice from my dad who is a technician/mechanic who has kept his 1986 Oldsmobile stationwagon going for almost 140k miles)

2) STOP, DROP, and ROLL so the people you're car pooling can watch you roll around in your bucket-seats like Bill Cosby trying to dance and hopefully some motorist will stop by and lend you some spare change or some gas.
 
hate to differ here, but I have been a mechanic for 27 years, and the reason they have a return line from the fuel rail back to the tank is to COOL the fuel back down so the injectors don't lock up from the elevated temps. They have, however changed this recently ( 2003, 2004 models) on some cars by increasing the pintle diameter on the injectors, and only running a supply line to the rail- no return line anymore.
 
if nothing else, say a family member is having a baby, got hurt, any emergency

wouldnt you like to have enough gas to get there without stopping?

if the family member lived close and you did fill up at half a tank every time
1. you'd be able to get there without worrying about filling up
and
2. it would seem like you are spending less on gas ($10 at a time but more frequent instead of $20)
 
Originally posted by: resinboy
hate to differ here, but I have been a mechanic for 27 years, and the reason they have a return line from the fuel rail back to the tank is to COOL the fuel back down so the injectors don't lock up from the elevated temps. They have, however changed this recently ( 2003, 2004 models) on some cars by increasing the pintle diameter on the injectors, and only running a supply line to the rail- no return line anymore.
That is correct, but what does it have to do with whether running your vehicle low on gas will/won't damage it?
 
Originally posted by: EMPshockwave82
if nothing else, say a family member is having a baby, got hurt, any emergency

wouldnt you like to have enough gas to get there without stopping?

if the family member lived close and you did fill up at half a tank every time
1. you'd be able to get there without worrying about filling up
and
2. it would seem like you are spending less on gas ($10 at a time but more frequent instead of $20)

number 2 is insanely stupid
 
Originally posted by: MAME
Originally posted by: EMPshockwave82
if nothing else, say a family member is having a baby, got hurt, any emergency

wouldnt you like to have enough gas to get there without stopping?

if the family member lived close and you did fill up at half a tank every time
1. you'd be able to get there without worrying about filling up
and
2. it would seem like you are spending less on gas ($10 at a time but more frequent instead of $20)

number 2 is insanely stupid
Agreed, and regarding #1, how many people live more than 1/2 tank away from a damn hospital? IMO, people who fill up at 1/2 tank just don't have any sense.
Why have a 25 gallon tank if you're only going to use 12 gallons? Are they so stupid that there's a real possibility that somewhere between 1/2 and empty, they'll simply lose their mind and forget to stop and fill up before it runs out?
"Oh, my tank is at 1/2, better fill up now 'cause I'll forget to check it again before it runs out".
 
Who ever the hell you are Munchies go back to bagging groceries for a living, you are not cutting it as a auto tech.

UHHH NO. Thats the bigeest load of BS if heard in a while. And I should know considering I build engines for my income. Run it dry it wont hurt nuffin. It will just sputter a bit, cant hurt

Its going to not makea diff. Ever hear of wtaer injection on gas engines?

I never heard so much BS in one thread from one member before.

These are the facts ;

All fuel injected vehicles from the factory have in the tank fuel pumps, these pumps are cooled by the fuel passing through them, the fuel pressure regulator on the fuel rail returns unused fuel from the engine back to the tank, this serves two functions, one, it acts as a reserve of fuel for full throttle and full load conditions, two, it acts to cool the fuel pump, the pump is continually pumping fuel from the tank to the engine and back to the tank again.

Most fuel pick ups inside the tank are raised a half inch of the bottom of the tank to prevent debris from being picked up but this is not to say that it cannot make it's way into your fuel system.

Running the tank dry is detrimental to the entire fuel system and you engine in the following ways ;

Condensation will form on the walls of the tank, this water will find it's way to the fuel system, water is damaging to fuel injectors because it is corrosive, also the ECM will try to correct a lean condition that is present because of the water, in newer vehicles with OBD II this will trip the check engine light, not to mention rusting the tank, fuel lines and fuel rail(s).

Water in a carb is not as bad but water will naturally go straight to the bottom of the fuel bowl, if the main metering jet(s) are raised slightly above the floor of the bowl then corrosion will occur inside the carb, incidentally all carbs have accelerator pump feed(s) at fuel bowl level so water will find it's way into the accelerator pump well thus corroding it.

While your at it, go back to school and learn how to spell.
 
Originally posted by: MAME
Originally posted by: EMPshockwave82
if nothing else, say a family member is having a baby, got hurt, any emergency

wouldnt you like to have enough gas to get there without stopping?

if the family member lived close and you did fill up at half a tank every time
1. you'd be able to get there without worrying about filling up
and
2. it would seem like you are spending less on gas ($10 at a time but more frequent instead of $20)

number 2 is insanely stupid

LOL!
 
Originally posted by: Roger
Who ever the hell you are Munchies go back to bagging groceries for a living, you are not cutting it as a auto tech.

UHHH NO. Thats the bigeest load of BS if heard in a while. And I should know considering I build engines for my income. Run it dry it wont hurt nuffin. It will just sputter a bit, cant hurt

Its going to not makea diff. Ever hear of wtaer injection on gas engines?

I never heard so much BS in one thread from one member before.

These are the facts ;

All fuel injected vehicles from the factory have in the tank fuel pumps, these pumps are cooled by the fuel passing through them, the fuel pressure regulator on the fuel rail returns unused fuel from the engine back to the tank, this serves two functions, one, it acts as a reserve of fuel for full throttle and full load conditions, two, it acts to cool the fuel pump, the pump is continually pumping fuel from the tank to the engine and back to the tank again.

Most fuel pick ups inside the tank are raised a half inch of the bottom of the tank to prevent debris from being picked up but this is not to say that it cannot make it's way into your fuel system.

Running the tank dry is detrimental to the entire fuel system and you engine in the following ways ;

Condensation will form on the walls of the tank, this water will find it's way to the fuel system, water is damaging to fuel injectors because it is corrosive, also the ECM will try to correct a lean condition that is present because of the water, in newer vehicles with OBD II this will trip the check engine light, not to mention rusting the tank, fuel lines and fuel rail(s).

Water in a carb is not as bad but water will naturally go straight to the bottom of the fuel bowl, if the main metering jet(s) are raised slightly above the floor of the bowl then corrosion will occur inside the carb, incidentally all carbs have accelerator pump feed(s) at fuel bowl level so water will find it's way into the accelerator pump well thus corroding it.

While your at it, go back to school and learn how to spell.

so it's better to refill at 1/2 way or so.

what about on a long trip. say you are driving 1200 miles and have to refill about 4 times. would you refill 4 times near empty? or 8 times near 1/2?

i'm thinking this 1/2 way thing only applies for normal at home conditions.
 
I think Roger is trying to say don't let it run right down, but there's no need to fill up at 1/2 a tank.


I normally try to fill up once it reaches about 1/4 tank. This will then give me enough fuel should anything happen to family members (who live ~60 miles away) so I can get there without having to worry about finding a petrol station that is open.


Confused
 
I normally fill up when it drops below the quarter full mark on the gas gauge, for a vehicle driven seldomly, having it filled all the time will decrease the chances of water condensation.
On long trips with multiple fill ups, waiting until it hits the red zone will not hurt anything, leaving the vehicle parked in a wet climate with the tank empty will cause condensation.
 
Originally posted by: Roger
I normally fill up when it drops below the quarter full mark on the gas gauge, for a vehicle driven seldomly, having it filled all the time will decrease the chances of water condensation.
On long trips with multiple fill ups, waiting until it hits the red zone will not hurt anything, leaving the vehicle parked in a wet climate with the tank empty will cause condensation.

WHo the hell is ever heard of roger the auto guy?
I am cutting it, building hopped 392's that seem to just never fail, and while I am an ENGINE guy, I do restore cars outside of my career as an performance mechanic. Asshat Youl probably whip out with something about how you were working on eninges before I was a drip on my mommas leg. Spare me, I do a good job, and btw I am not an auto tech. I am an IHC performance engineeer.
 
Originally posted by: Roger
Who ever the hell you are Munchies go back to bagging groceries for a living, you are not cutting it as a auto tech.

UHHH NO. Thats the bigeest load of BS if heard in a while. And I should know considering I build engines for my income. Run it dry it wont hurt nuffin. It will just sputter a bit, cant hurt

Its going to not makea diff. Ever hear of wtaer injection on gas engines?

I never heard so much BS in one thread from one member before.

These are the facts ;

All fuel injected vehicles from the factory have in the tank fuel pumps, these pumps are cooled by the fuel passing through them, the fuel pressure regulator on the fuel rail returns unused fuel from the engine back to the tank, this serves two functions, one, it acts as a reserve of fuel for full throttle and full load conditions, two, it acts to cool the fuel pump, the pump is continually pumping fuel from the tank to the engine and back to the tank again.

Most fuel pick ups inside the tank are raised a half inch of the bottom of the tank to prevent debris from being picked up but this is not to say that it cannot make it's way into your fuel system.

Running the tank dry is detrimental to the entire fuel system and you engine in the following ways ;

Condensation will form on the walls of the tank, this water will find it's way to the fuel system, water is damaging to fuel injectors because it is corrosive, also the ECM will try to correct a lean condition that is present because of the water, in newer vehicles with OBD II this will trip the check engine light, not to mention rusting the tank, fuel lines and fuel rail(s).

Water in a carb is not as bad but water will naturally go straight to the bottom of the fuel bowl, if the main metering jet(s) are raised slightly above the floor of the bowl then corrosion will occur inside the carb, incidentally all carbs have accelerator pump feed(s) at fuel bowl level so water will find it's way into the accelerator pump well thus corroding it.

While your at it, go back to school and learn how to spell.

Great info but...uh....bad spelling advice. 😉
 
Originally posted by: Munchies
Originally posted by: Roger
I normally fill up when it drops below the quarter full mark on the gas gauge, for a vehicle driven seldomly, having it filled all the time will decrease the chances of water condensation.
On long trips with multiple fill ups, waiting until it hits the red zone will not hurt anything, leaving the vehicle parked in a wet climate with the tank empty will cause condensation.

WHo the hell is ever heard of roger the auto guy?
Every single person on this forum has. None of them have heard of you, and right now no one believes you about building anything, whether you actually do or not, because you're acting like an asshole.

I am cutting it, building hopped 392's that seem to just never fail, and while I am an ENGINE guy, I do restore cars outside of my career as an performance mechanic. Asshat Youl probably whip out with something about how you were working on eninges before I was a drip on my mommas leg. Spare me, I do a good job, and btw I am not an auto tech. I am an IHC performance engineeer.

Yeah, way to make yourself look like a complete jackass, and therefore even LESS credible.
 
Originally posted by: Munchies
Originally posted by: Roger
I normally fill up when it drops below the quarter full mark on the gas gauge, for a vehicle driven seldomly, having it filled all the time will decrease the chances of water condensation.
On long trips with multiple fill ups, waiting until it hits the red zone will not hurt anything, leaving the vehicle parked in a wet climate with the tank empty will cause condensation.

WHo the hell is ever heard of roger the auto guy?
I am cutting it, building hopped 392's that seem to just never fail, and while I am an ENGINE guy, I do restore cars outside of my career as an performance mechanic. Asshat Youl probably whip out with something about how you were working on eninges before I was a drip on my mommas leg. Spare me, I do a good job, and btw I am not an auto tech. I am an IHC performance engineeer.
Without ever meeting you, I am going to guess that you went to automotive engineering school because you failed English.
 
Originally posted by: notfred
Originally posted by: Munchies
Originally posted by: Roger
I normally fill up when it drops below the quarter full mark on the gas gauge, for a vehicle driven seldomly, having it filled all the time will decrease the chances of water condensation.
On long trips with multiple fill ups, waiting until it hits the red zone will not hurt anything, leaving the vehicle parked in a wet climate with the tank empty will cause condensation.

WHo the hell is ever heard of roger the auto guy?
Every single person on this forum has. None of them have heard of you, and right now no one believes you about building anything, whether you actually do or not, because you're acting like an asshole.

I am cutting it, building hopped 392's that seem to just never fail, and while I am an ENGINE guy, I do restore cars outside of my career as an performance mechanic. Asshat Youl probably whip out with something about how you were working on eninges before I was a drip on my mommas leg. Spare me, I do a good job, and btw I am not an auto tech. I am an IHC performance engineeer.

Yeah, way to make yourself look like a complete jackass, and therefore even LESS credible.
I was only pissed because he thinks im not a good auto tech, I am justa s good if not better than anyone out there, I have no beef. I grilled it and I ate it.
 
Originally posted by: Munchies
Originally posted by: Roger
I normally fill up when it drops below the quarter full mark on the gas gauge, for a vehicle driven seldomly, having it filled all the time will decrease the chances of water condensation.
On long trips with multiple fill ups, waiting until it hits the red zone will not hurt anything, leaving the vehicle parked in a wet climate with the tank empty will cause condensation.

WHo the hell is ever heard of roger the auto guy?

:laugh:
 
Originally posted by: Mwilding
Originally posted by: Munchies
Originally posted by: Roger
I normally fill up when it drops below the quarter full mark on the gas gauge, for a vehicle driven seldomly, having it filled all the time will decrease the chances of water condensation.
On long trips with multiple fill ups, waiting until it hits the red zone will not hurt anything, leaving the vehicle parked in a wet climate with the tank empty will cause condensation.

WHo the hell is ever heard of roger the auto guy?
I am cutting it, building hopped 392's that seem to just never fail, and while I am an ENGINE guy, I do restore cars outside of my career as an performance mechanic. Asshat Youl probably whip out with something about how you were working on eninges before I was a drip on my mommas leg. Spare me, I do a good job, and btw I am not an auto tech. I am an IHC performance engineeer.
Without ever meeting you, I am going to guess that you went to automotive engineering school because you failed English.

Nope. I never went to school, all my auto knowledge has been passed down through my family, I am goign to colledge to become a firefigter pretty soon though, and run my shop as a part time deal.
 
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