My car doesn’t have a range calculator, all it’s got is the bars. I fill it up either at 2/6 when I stop for a meal, or in the first available station once it gets down to 1/6.
Last year I ran out of fuel due to a stretch of gas stations being closed on Sunday. That’s got to be the stupidest reason to need to call the insurance company there is, and yet, highway assistance does have a set rate for it. I take that to mean it’s actually pretty common.
Here in Minnesota, I don’t go much below a 1/2 tank in the winter. Now in the summer I usually wait until the gauge reads 1/4. Rarely do I let it go longer than that.
I fill up at 1/4 tank. That’s usually once a week, and I drive by the gas station on the way to work so it works well.
I live pretty rural, so I don’t like going below 1/4 tank.
I’m another who doesn’t use the “miles to empty” thing. I’ll go to about half-way between empty and 1/4 on the dial which I know from experience gives me about a 2 gallon cushion.
I’ve put 160K miles on my current 2003 car. At about 300 miles per tank that’s a lot of sample data.
In that time I have often driven it (in familiar surroundings) until the miles-to-empty counter was under 5 miles. I’ve occasionally taken it down to 1 mile to go. It has never once run out of fuel. When I fill up from <5 miles to go it takes the full rated capacity of the tank plus a quart or so.
The car gets about 18mpg city / 25 highway, so that last 5 remaining miles is roughly 1 quart of fuel. IOW, the physical tank capacity seems to be about 1/2 gallon more than the manual says, and the miles-to-go calculation *probably *has some extra reserve built in. Reserve I’ve never burned into.
I do see that the miles-to-go figure has some instability when you get down under about 60 miles. Or said another way, it’s reacting quickly to your instantaneous gas mileage. Which is good. On the freeway on level ground in light traffic I’d be OK passing a gas station while showing 50 miles remaining and knowing the next gas is 45 miles away. I would NOT do that if I was about to start a long climb into the mountains or if traffic might clot. In adverse conditions the range *could *drop enough that I’d be screwed a mile short of that next gas station.
OTOH, at 5 miles from my usual home gas station with 7 miles showing remaining I’m totally unconcerned. The biggest risk there is simply me forgetting to stop for gas and driving past it too far to turn back. Oops.
Tomorrow I replace this trusty car with a newer one. I’ll be interesting to learn how accurately its mileage countdown performs.
Cool. That comports with my observation. 69-94 miles it says for my Mazda 3, and my observation was “at least 50 miles.” And the 2.3 gallon cushion also almost matches my numbers. I estimated a cushion of 2.5-2.7 gallons when the it reached E or 0 on the range calculator, so pretty close.
my my grandfather used to tell me that every time you open the gas tank some of the gasoline vaporizes and you lose that portion. The more frequently you do this, the more gas you lose. His goal was to fill up as infrequently as possible, letting the gauge get close to empty. This seems like a good method/Theory, however there are times when you must have it full.
I always heard it was bad for the fuel pump if you ran it near empty:
John Stossel did a thing on this back when he worked for 20/20. If I remember correctly, he drove his car for 50 miles (until he finally ran out) after the display said he had zero miles left.
Apparently, manufacturers do this on purpose because people are stupid basically.
For a long time I had a Pontiac whose gas gauge would stay pegged at F (full) for a long time, whereas the 1/4 tank mark really meant “buy gas NOW”. It went dry on me several times with the needle still not down to the E mark.
As a consequence I’m a lot more leery of being in a car where less than 1/4 tank is showing on the gauge. I don’t care for the “tromp to gas station and come back with a jerry can” routine.
If the manufacturers are compensating for people’s stupidity by displaying “0 miles” when there are really 50 miles left, soon people will start discounting this, and mentally adding 50 miles to the displayed figure. Then, the manufacturers will have to re-calibrate the stupidity compensation, so that “0” is now really 100. Eventually, display inflation will mean that even with a full tank the display will tell you that you ran out of gas last week.
Flew small aircraft for a living and have 10,000 + hours PIC. I am not a bold pilot, I am an old pilot partly because even with the best planning, Mother Nature always has surprises and I always had enough extra to get it done. Sometimes you have to just hope you make it to land or to the only airport in range.
Always knew that there was fuel at the home FBO but there are three totally unless things in Aviation:
Runway behind you.
Altitude above you.
Fuel on the ground.
And.
Only time I ever had too much fuel was when I was on fire. ( now that was scary )
Many places pilots can’t pull over to the curb and call for help. Kinda need to keep that in mind also.
Airlines have a different set of problems when it comes to fuel load and the pilots pretty much have to follow the regulations. BUT !!! If it goes wrong, they survive and it was just running out of fuel, they are on the hook anyway. Be nice to your pilots, they are sitting in the tip of the arrow and are the first ones to the crash site.
Yeah, they actually touched on this in the 20/20 piece. They said they don’t to compensate for this sort of thing in the European markets. But for some reason, Americans still expect their cars to go even when the meter says empty.
Running low on fuel can damage your fuel pump and more.
"Gasoline not only fuels the vehicle, but it also functions as a coolant for the electric fuel pump motor. In modern cars, this pump sits in the middle of the gas tank filled with cool gasoline. A near-empty tank can cause the fuel pump to suck in air and overheat, causing significant damage to the pump.
Each time you neglect pumping gas, gunk from the bottom of the gas tank could get caught in various components of the vehicle. This sediment in your tank can foul the fuel filter. If the fuel filter doesn’t catch the sediment, you run the risk of clogging a fuel injector.
When a diesel runs dry, the injector pump fills with air and the vehicle won’t start by simply adding more diesel fuel. A tow truck and mechanic may need to get involved to tow the vehicle, remove filters, pressure-blow the fuel lines before adding fuel and prime the engine. Because of this, maintaining a full tank with a diesel engine is even more critical than with a gasoline engine."
I reset my trip odometer whenever I fill up. I fill up after the trip odometer hits 300 miles. Sometimes there’s a quarter tank left at that point, sometimes there’s less than a gallon. But 300 miles appears to be the minimum full-tank range of my car (2012 Mazda 3).
The range calculator gives me almost 500 miles on a full tank but I’ve never hit that; most I’ve gotten out of it with a lot of non-trafficky highway driving is about 450. 300-350 is most frequent.
Well, apparently they are doing this, seeing PastTense’s link. It’s been this way for quite awhile, as far as I remember. Even twenty five years ago, the needle being on E in my 1985 Chevy Chevette still meant I had about a good 50 miles to go.
A friend of mine from Germany confirms this. He told me Germans would be irritated if E or “zero” did not mean just that. None of this cushion business. 
Perhaps the more litigious U.S. is a factor here. It’s less risky from a manufacturer’s perspective to sacrifice accuracy and calibrate low to ensure that they never get sued for the consequences of fuel exhaustion before it reads zero.
I don’t let mine get much below half. I would think that would be a good guideline for anybody living in an area that has the potential for disaster: hurricane, earthquake, etc.
I thought it somewhat had to do with the physical construction of fuel gauges, with how the floater would hit the top before the tank was full and the bottom before it was empty, hence the effect of the car staying on “F” for like 50 or more miles before ticking down and, conversely, the similar sort of effect on the “E” side of the gauge.
I also assume this is more historical than current, but wasn’t that the reason that fuel gauges stayed on F for so long and could drive on E for awhile?