I often end up filling my gas tank when the car is empty. Today my gas light went on about 15 miles before I got to work. I'll fill it later when I leave. Didn't have time this morning. Is it still considered bad to wait until your car gets that low to fill it? I would have used the search function but I was at a loss on what search terms to use. It's early.
"E" Running on empty
- Thread starter buster
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I usually don't fill up until the needle is on E for a while, been doing it for 11 years and have no problem...although I did run out of gas once, which sorta sukked.
If you rarely run the tank that low, sediment and other gunk might accumulate near the bottom. In that case, it would be bad to run it low because you'd start to pick that stuff up. The problem is worse with frequent use of gas that is cheap and/or from stations with infrequent refills.
If you frequently run the tank almost all the way down and use decent gas, you won't really have that problem as much.
Other variables, of course, are the quality of your fuel filter, some of the specifics of your engine, and your driving habits.
If you frequently run the tank almost all the way down and use decent gas, you won't really have that problem as much.
Other variables, of course, are the quality of your fuel filter, some of the specifics of your engine, and your driving habits.
The real problem is that the electric fuel pump depends on both the fuel passing through, and the fuel it is submerged in (if tank-mounted) to cool itself. Without that they can burn out quickly.
Yes, tank mounted pumps, common nowadays, rely upon fuel for cooling. Personally, I rarely allow my car go go much below a half-tank. Of course, with a 12 gallon tank that confers over 500 miles of range (more if you're willing to play chicken and take it all the way down), that's not a big deal. I do this for reasons unrelated to fuel quality or pump durability. For at least half the year, we are subject to devastating hurricanes (as everyone knows). One of the problems here is that as soon as there's a hint that a 'cane is headed in, everyone races to the gas station for a fillup, resulting in absurd gas lines, and stations running dry (which further fuels panic (pun intended)). I just make it a policy that I'll always have enough gas in the Prius to make an evacuation getaway without the need to stop first for gas. Only occasionally do I have less than 250 miles of range available. As a further O/T point, the Toyota/Lex hybrids are great cars for such getaways, since their gas engines are almost always off when at a standstill, and hurr-evacs always involve much sitting still in traffic.
Added side benefit: running out of gas is simply never a concern.
Added side benefit: running out of gas is simply never a concern.
I have always wondered about this and never gotten a good answer: does the fuel pump get adequately cooled by the fuel running through it, or does it rely also on fuel surrounding it in the gas tank?
I suspect it only needs the fuel running through it. It seems it would be foolish to design in a need to actually be submerged. If true then it will be fine until it actually sucks air, or partial air.
I run my car to E almost all the time. In fact, with my trip computer, I know that when the range reading goes to "----" I have exactly a quarter gallon left, so I can confidently run it to within a couple of miles of empty before filling. The number of gas stops I avoid each year is probably worth a couple hundred $ in time saved. (My wife's car (Infiniti I30) has a lousy fuel gauge so you really have very little idea how much gas is left, so I usually fill it earlier.)
Anyway I also run a little MMO in the fuel. I figure that helps lube the pump, which probably helps it run cooler.
I suspect it only needs the fuel running through it. It seems it would be foolish to design in a need to actually be submerged. If true then it will be fine until it actually sucks air, or partial air.
I run my car to E almost all the time. In fact, with my trip computer, I know that when the range reading goes to "----" I have exactly a quarter gallon left, so I can confidently run it to within a couple of miles of empty before filling. The number of gas stops I avoid each year is probably worth a couple hundred $ in time saved. (My wife's car (Infiniti I30) has a lousy fuel gauge so you really have very little idea how much gas is left, so I usually fill it earlier.)
Anyway I also run a little MMO in the fuel. I figure that helps lube the pump, which probably helps it run cooler.
The fuel pickup is down at the bottom of the tank anyway; running low won't grab junk that wasn't already there anyway. Unless it floats on top of gas, which is unlikely.
I've run out of gas once on a FI car, just added more and was on my way.
Having gone down to an indicated 1/8 and discovered I could only add 3/4 of my tank's rated capacity, I'm confident in my gauge that E is "enough". Only when you fill your tank will you have the same confidence.
Incidentally modern tanks have a bit of an airspace by design, for smog reasons.
I've run out of gas once on a FI car, just added more and was on my way.
Having gone down to an indicated 1/8 and discovered I could only add 3/4 of my tank's rated capacity, I'm confident in my gauge that E is "enough". Only when you fill your tank will you have the same confidence.
Incidentally modern tanks have a bit of an airspace by design, for smog reasons.
I always go down to the light coming on and still have at least 1.5 gallons of a 13 gallon tank left on the Toyota. (and if the light goes on during my 50 mile one way commute I wait till I get home/work before filling up)
No problems with my Subaru, Toyota, VW, Fords or Chevys over the years.
Bill
No problems with my Subaru, Toyota, VW, Fords or Chevys over the years.
Bill
Don't want to EVER do that with a dual tank Ford pickup...
$$$$$
Cheers!
p.s. My current wife drove the SVX for almost 10 years before she ever even knew that there was a fully functional low fuel warning light.
Query: if it never is allowed to go on how do you know that it actually works?
$$$$$
Cheers!
p.s. My current wife drove the SVX for almost 10 years before she ever even knew that there was a fully functional low fuel warning light.
Query: if it never is allowed to go on how do you know that it actually works?
In my car, when it hits E there's still 1-2 gallons left in the tank. I've never hit E before filling it, however. Gotten pretty close though, then chickened out. Maybe it's a mental thing 
Originally Posted By: d00df00d
If you rarely run the tank that low, sediment and other gunk might accumulate near the bottom. In that case, it would be bad to run it low because you'd start to pick that stuff up.
The fuel pump always draws fuel from the bottom of the tank.
If sediment and water floated on top of the fuel, then it would be a problem.
If you rarely run the tank that low, sediment and other gunk might accumulate near the bottom. In that case, it would be bad to run it low because you'd start to pick that stuff up.
The fuel pump always draws fuel from the bottom of the tank.
If sediment and water floated on top of the fuel, then it would be a problem.
I try to keep the gas filled up over the 1/2 mark in winter to lessen the effects of condensation in the tank at night.
But when temps are mild, I'll let it run down until near E and then fill up. I don't know what the previous owner was like as far as fill up habits, but my Explorer does have the original fuel pump at 157,000 miles.
But when temps are mild, I'll let it run down until near E and then fill up. I don't know what the previous owner was like as far as fill up habits, but my Explorer does have the original fuel pump at 157,000 miles.
My car accelerates better when very close to empty. Gas here is contaminated with ethanol, which dissolves away any condensation or frost, so I don't worry about that.
My car sees empty all the time. In the three years that I've had it the fuel light usually comes on before I get myself to fill it up unless I have a long trip then I fill it up even if it's not empty yet. I usually reset the trip meter after each fill up so at around 330-350ish miles I know I should fill up so another indicator besides the light. And I don't know if it's psychological but I also notice that my car seems to be just a bit more peppy when it's nearly empty. The 80ish pounds of gas when full can't make that of a big difference in weight.
the butt dynamometer is surprisingly sensitive
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Originally Posted By: buster
I often end up filling my gas tank when the car is empty. Today my gas light went on about 15 miles before I got to work. I'll fill it later when I leave. Didn't have time this morning. Is it still considered bad to wait until your car gets that low to fill it?
As long as you don't completely run out of gas, it shouldn't be a problem. In my owner's manual it states that running out of gas may cause the cat converter to fail, but I don't exactly understand how. Can someone shed some light on this?
FYI, I usually just wait until my gas light stays on solid before I start looking for a gas station. At that point I still have approx. 2 gallons of fuel left and can easily go for another 50 miles considering the way I drive.
I often end up filling my gas tank when the car is empty. Today my gas light went on about 15 miles before I got to work. I'll fill it later when I leave. Didn't have time this morning. Is it still considered bad to wait until your car gets that low to fill it?
As long as you don't completely run out of gas, it shouldn't be a problem. In my owner's manual it states that running out of gas may cause the cat converter to fail, but I don't exactly understand how. Can someone shed some light on this?
FYI, I usually just wait until my gas light stays on solid before I start looking for a gas station. At that point I still have approx. 2 gallons of fuel left and can easily go for another 50 miles considering the way I drive.
The Honda Odyssey would drive you guys nuts. It is a flat bottomed tank, and when the light comes on you typically have 5 gallons left, and it is a 20 gallon tank! I had to replace an electric fuel pump on an 1987 Taurus before 100,000 miles, and since then I try to refill before 1/4 tank because of what I read about cooling of the fuel pump.
QP:
I think the answer to your question probably boils down to misfires. Assuming that the fuel flow doesn't end all at once, perhaps some air gets in the lines with the last of the gas, causing the injectors to start feeding an uncontrolled/unknown mixture into the cylinders. If the compromised charge doesn't light off correctly, you may end up with large pulses of unburned/improperly burned fuel in the cat. Once that happens, and the cat tries to burn it all off, the cat might end up burning itself off...
I think the answer to your question probably boils down to misfires. Assuming that the fuel flow doesn't end all at once, perhaps some air gets in the lines with the last of the gas, causing the injectors to start feeding an uncontrolled/unknown mixture into the cylinders. If the compromised charge doesn't light off correctly, you may end up with large pulses of unburned/improperly burned fuel in the cat. Once that happens, and the cat tries to burn it all off, the cat might end up burning itself off...
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