Q: is driving with low fuel dangerous for the car? Does driving often with low fuel also do damage to the engine?
Some feel it can damage the fuel pump which can over-speed if run dry…Running out of gas is no fun. Why risk it?
If you don’t run out of fuel, no and no.
The fuel in the tank helps keep the pump cool. So one idea is that running it too low can damage the pump. I have no idea. I can’t think of any good reason to push these kinds of things.
Play with fire, you’ll get burned…one day you’ll forget to gas up at the MOST inconvenient time…
Oh, I don’t know texases. I come from a rather religious family where people are fond of saying “the Lord works in mysterious ways.” Think of all of the exercise you get by walking, and all of the patience you learn by waiting by the side of the road when you run out of gas. And think of all of the character building that comes from dealing with completely screwing up whatever it was you were on your way to.
Running low won’t hurt the pump unless the fuel level is low enough to cause sputtering or occasional bucking and jerking.
As long as the pump is full gasoline overheating won’t be a problem.
The pump uses gasoline as a lubricant (albeit a poor one) to protect the pump bushings. When air hits the pump any gas is wiped away very quickly and it becomes metal on metal. With the high RPMs those pumps turn damage can start to occur pretty quickly.
The only danger would be getting stranded or possibly having a car hiccup and stall at a bad time; say as you’re trying to clear some railroad tracks or sweating out that loaded semi that’s 3 car lengths off of the rear valance.
I’ve read that there are more fuel pump failures on cars driven by younger people. Most of them only put a few dollars worth in at a time, therefore the tank stays low so there may actually be some truth to the theory of the gas helping control the heat of the fuel pump. Of course it could also be that many young people drive pieces of junk too. I usually fill up with a least a 1/4 tank left and have only had 3 fuel pumps wear out in about 1 million miles of driving and only two of them were electric fuel pumps, the other one was an old mechanical pump that started leaking.
Running out of gas in the middle of a busy highway can be dangerous for the car and also for the occupants. Why would you want to take that chance?
Also, have you or anyone you care about ever needed to drive to the emergency room? Does having to stop for gas along the way sound like a bad idea to you? It does to me.
A recent study indicated that keeping your fuel tank no more than ¼ full will reduce the weight of your car and increase your mileage an estimated 0.00026% or about $0.012 per tank.
The only real disadvantage to driving with fuel at a low level is psychological. Low fuel does no damage to the fuel pump or the engine, but it can cause great anxiety in many drivers. Review the above replies and you will see the pattern.
Many modern drivers are diligently following grandpa’s strict advice about filling up as soon as the gauge drops to the 1/4 mark. It made sense for him. Those were the days when filling stations were few and far between, and none were open 24/7. Times have changed, haven’t they?
I’ve looked, and automotive fuel pump manufacturers warn against routinely running low on gas.
And it can be even worse should you sputter to a stop in a high crime area late at night. Or in the middle of a snowstorm late at night.
There’s absolutely no upside to constantly running with your low fuel light lit. No upside whatsoever.
SteveF; I know several people who get their psychological highs from trying to drive on vapors. If you have an other wise dull life, as pointed out by others, try living dangerous. I once worked with a guy who stayed in airport cocktail lounges drinking (at company expense) till the very last moment and was always last to get on his plane. He missed several times. I stopped joining him for drinks and boarded early.
My wife never lets the tank get below 1/4. Part of her medical training is to eliminate the chances for things getting screwed up. We live in an area of low population density and traveling at night in the mountains forces you to have lots of fuel.
Hey Doc, thanks for the advice. I know that when my low fuel warning light comes on, I have at least 50 miles remaining. And no matter where I am, there is always a cluster of all-night filling stations at the next set of intersections. So what’s the urgency? But do things your own way. You’re happy, so am I.
SteveF…I lived in Alaska for a couple of years and I can testify that sometimes there is not a cluster of gas stations nearby. In fact, a few times while I was traveling I felt like a prospector finding a waterhole in the middle of the desert when I saw an open gas station. When my gas tank gets around 1/4 full I start looking for the nearest Kroger with gas pumps. It’s just something I do now even though I no longer live in Alaska or Northern Maine where gas stations were also few and far between.
" But keeping it full costs more.’’ is a gripe I often hear.
The answer to that; “just once.”
"Just once ? " they query with amazement.
Yes just once. If your gas budget works when close to empty then the exact same budget will work close to full.
Fill it up just once, then continue to put the exact same weekly budget in the tank.
That’s true, Ken. Saturday is my fill up day, $30 usually fills the tank. Friday comes around I’m just getting down to a 1/4 tank. I know it will run me about $30 (unless I’ve been on a road trip) to fill it back up for the week. Of course that’s at current prices…subject to change and most likely will it sounds like. 
Running very low/out of fuel may damage the fuel pump. Or it may not. All I can say is I rarely let my tank get below a quarter and I’m still on the original fuel pump in my 1994 with over 260K on the odometer. If you can afford it, why not just fill up when it dips below ½ tank?
If you keep it somewhat full, the crud at the bottom of the tank is much diluted. You also have gas to go at a moment’s notice and will never get caught short on one of those days when everything is going wrong.
"If you can afford it, why not just fill up when it dips below ½ tank?" (If you can afford it) ????? How is it more expensive (or less for that matter) to fill up less often?
Of course if you keep it reasonably full and never need to (get gas right now!) you will always have the ability to choose the station with the lower fuel cost. So I would say, you can save money by getting gas when and where it is less expensive, which you can do as long as you don't tend to drive on "E".