But it needs it, Kramer! It needs it bad!
May 8, 2008 1:20 AM   Subscribe

Tank on empty -- how far can your car go on an empty tank? Basically a collection of statistics and stories from users on just how far they pushed their car on reserve fuel. (via) posted by spiderskull (45 comments total) 2 users marked this as a favorite
 
The user-posted stories really make the site. It's an entire community based around the notion of running out of gas. Can we Rule 34 this?
posted by breath at 1:37 AM on May 8, 2008


Also, mandatory cultural reference.

Try this one instead.
posted by three blind mice at 2:45 AM on May 8, 2008


Are most people unaware of how far they can get on the reserve tank?

I have a Smart which isn't in the TankOnEmpty database. It has exactly 5 litres of fuel in reserve, which gets me about 50 miles down the motorway, as long as traffic is flowing freely. I've twice run it out completely, which didn't seem to do it any harm.
posted by roofus at 3:16 AM on May 8, 2008


IANAMechanic, but I read a comment on one of these forums by someone who was; he said that letting the fuel level get very low was dangerous, as the fuel pump was inside the gas tank and depended on immersion in gasoline for lubrication. Running it too long "dry" could ruin it and necessitate a $500-1,000 replacement.

There's every possibility that this is completely ludicrous, and that everyone knows that the fuel pump is located on a bracket next to the battery, with convenient lube points that most people grease every two weeks, with a light on the dash indicating the next lube interval. I would have no idea. So I hope I haven't made myself look really stupid here.

If that is the case then please keep in mind that I know quite a bit about, like, biology and stuff, and am generally a very kind, albeit dim, person.
posted by Turtles all the way down at 3:41 AM on May 8, 2008


Turtles, look at the top rated story on the site. Also, a couple below that, a guy talking about his burned out fuel pump.
posted by knave at 3:45 AM on May 8, 2008


I'm also disappointed that they are specifically talking about miles after the warning light, because I've never kept track of that. But I've gone 506 miles on a single tank in a Maxima, which I thought was pretty cool (averaged 31mpg -- hypermiling style).
posted by knave at 3:47 AM on May 8, 2008


Pardon me for being from the twenty-first century or thereabouts, but...WTF is this "mile" you speak of?

Honestly, how hard is it to copy-paste a little snippet of conversionatoriastic code into one's PHP-FU/Python-ate-my-kittenz/Ruby-hold-the-mayo CMS thingy? (I'm not a developer -- really, I'm asking. Is that hard? If so, would you hold it against me?)

At any rate, I had to go through the sweat and toil and tap-clicking my ass to Google to do the conversion for me so I could inform the site that my extremely masculine butter-yellow sub-compact car has PRECISELY 100 km of travel left when the red light comes on.

(One doesn't fare quite as well under the Imperial system, under which conditions the car will only drive some additional 63 miles.)

I know this because I drive by the tripmeter. I reset to zero at various strategic points, and then go by the numbers. I know my exit from the highway on my way to work is at South 53 km, for example, or that Tim Horton's is at South 44 km. On my way home, my last chance for gas is at North 33. Even if it's very foggy or rainy or snowy I always know to pull aside for my off-ramp at N-66.7. It's a great way to drive if, like me, you tend to go away into lala-land while commuting and thus are prone to missing your exit and driving away to foreign cities without realizing it. Um. Not that that's ever happened to me. Ahem.
posted by CheeseburgerBrown at 3:56 AM on May 8, 2008


John Stossel covered this topic as well; the video is on this page under "E Means Empty: Myth or Fact". It makes sense to me that manufacturers would be conservative with their fuel gauges both because more frequently running out of gas would make for unhappy customers and the aforementioned issue with the fuel pumps.
posted by TedW at 4:17 AM on May 8, 2008


breath, the car running out of gas and ensuing sex has been rule 34'd since before rule 34 existed.
posted by substrate at 4:25 AM on May 8, 2008


Last link needs a Seinfeld disclaimer. NSFSH or something similar.

Good thing I hadn't had any breakfast yet.
posted by Eideteker at 4:35 AM on May 8, 2008 [1 favorite]


but...WTF is this "mile" you speak of?

Well, it's a little akward to measure distances in intervals of 1,613km. Using the term "mile" is just easier.
posted by three blind mice at 4:48 AM on May 8, 2008


This post got me thinking about mis-calibrated gauges. Anyone know why there isn't a more precise gauge in automobiles? Kind of silly these days IMO.
posted by zerobyproxy at 4:52 AM on May 8, 2008


I've done almost 30 miles in my Honda Civic, from the point at which the empty light came on. When the engine began misfiring, due to inadequacy of the fuel supply, I knew it was time to give up this silly experiment and pay the ludicrous motorway service station prices to get me the rest of the way home.

However, I see from that list that I may have had as much as two or three gallons left in reserve. In which case, I wonder why it was misfiring? I'm sure it wasn't paranoia, because I expected there to be at least a full gallon, and I get far more than 30 miles to the gallon when motorway driving.
posted by PeterMcDermott at 5:01 AM on May 8, 2008


Anyone know why there isn't a more precise gauge in automobiles?

For example, why does my speedometer consistently show that I'm going 3-5 mph slower than my SatNav does?

Given that my satnav (a TomTom 510) shows me where all the Speed Cameras are, it seems unlikely that I'd really be doing 55 mph as I travel past the camera. But that's what my car's built-in speedometer tells me.

Is Honda acting as the surreptitious evil arm of the nanny state?
posted by PeterMcDermott at 5:08 AM on May 8, 2008


Your speedometer is calibrated to the size of your wheels and tires, so as your tires wear its reading will become inaccurate. I have heard that auto manufacturers will calibrate them a little high so that people feel like they're going faster than they actually are, but the one in my car seems about spot on with my GPS.

I know for a fact that my former employer (that built avionics for small aircraft) built a fudge factor in to the airspeed indicator at the behest of our customer. Seems the airplane manufacturer wanted to show that their aircraft could fly 2 or 3 knots faster than they actually could...

Also, accurate measurement of a volume of liquid is tricky. Accurate measurement of a volume of liquid that is sloshing around in a tank is just crazy talk.
posted by backseatpilot at 5:16 AM on May 8, 2008


I never ran out of gas in my 92 Saab convertible, but I had read that the warning light meant I had 2 gallons left. I figured it that equalled about 40 miles, and I'm sure I cut it really close several times.

My Saab gave up the ghost, so now I have a 20 year old Cadillac DeVille. ("Pimpin'!" to quote my daughter.) It has an electronic dash. The gas gauge goes from reading out the number of gallons, down to 2, then it goes to E, then the E starts flashing. I had a Caddy years ago, and when the E was flashing, I probably had enough gas for 10 more miles. I started for work the other day, and noticed the readout said E but wasn't flashing. There is a gas station a block away, the opposite direction from work which is about 4 miles. I decided to get gas after work at a station near the office. I got a block away and ran out. Somehow, it's the car's fault for not blinking at me.

Cool link. It's a common experience that we don't talk about enough. Let's open up the national conversation on running out of gas!

By the way: don't you hate those people who say "I never let my car get under a half a tank!" Rich people, man.
posted by Fuzzy Skinner at 5:31 AM on May 8, 2008


>I have heard that auto manufacturers will calibrate them a little high so that people feel like they're going faster than they actually are


Mine's out by about 10%.

As to petrol, now that I'm not a student, I'd prefer not to gunk up the fuel pump. My POS car has enough problems.
posted by pompomtom at 5:34 AM on May 8, 2008


In which case, I wonder why it was misfiring?

Maybe the gas sloshed away from the fuel pump causing momentary starvation?
posted by knave at 5:36 AM on May 8, 2008


Peter: for what it's worth my (1996 DX US model) Civic's fuel gauge level is very sensitive to the angle of the car -- if I am going downhill, for example, the gauge reads a bit more full (as much as an eighth of a tank more full depending on steepness) than if I am going uphill, and a prolonged left turn will make the fuel level look slightly higher than a prolonged right turn. I understand this is because the sensor (like the fuel lines) is at the right front corner of the tank.

So if the yellow warning light comes on when I am generally going uphill a lot, it would probably mean I have 50 miles of driving left, but if it were to come on while I have been going mostly downhill, it would probably mean more like only 30 miles of driving left. (Cheeseburger, that would be something like 80 km and 50km respectively, in case you were fretting and having trouble with the multiplying by 1.6 thing.)

I too find on my Civic that the speedometer reads a few mph higher than external sources tell me I am going. I am not sure your model but a mechanic once told me it had to do either with DXs having slightly smaller tire diameter than other models, or with some years' DX being geared differently (I haven't really pursued the issue so I don't know if either of those is really true, but my Civic's shift points do seem a bit different).

I've never tried to run my car dry though, for fear of the fuel pump burn-out factor; in fact I try not to let it get below a quarter tank if I can help it.
posted by aught at 5:54 AM on May 8, 2008


Anyone else wondering what Rule 34 is?

Per the first comment... I'm not sure if I've been bettered by this knowledge, but assuming my office doesn't have a firewall I'll probably be putting it to the test later today.
posted by kristinahoge at 6:00 AM on May 8, 2008


Don't forget to leave your spam on this page.
posted by Fuzzy Skinner at 6:08 AM on May 8, 2008


letting the fuel level get very low was dangerous, as the fuel pump was inside the gas tank and depended on immersion in gasoline for lubrication

I don't think most fuel pumps would immediately self-destruct when the car ran empty, but repeated occurances are certainly not good. The gas keeps the pump cool as well.

Another possible problem (according to some, like my dad) is that when the fuel level is very low, the impurities which have settled to the bottom are now at a higher ratio to the remaining fuel, which can clog the filter. I have no idea if that's been proven, but it seems to make sense.
posted by Fuzzy Skinner at 6:17 AM on May 8, 2008


I don't trust my digital speedometer. I miss the dial, which at least felt to me like it wasn't pretending to accuracy that wasn't there.
posted by Karmakaze at 6:18 AM on May 8, 2008


By the way: don't you hate those people who say "I never let my car get under a half a tank!" Rich people, man.


With the rate of price increases in gas as of late, one would think its only the rich who wait until the tank is nearly empty to fill it up again.
posted by Atreides at 6:28 AM on May 8, 2008


This site isn't useful at all because it doesn't differentiate between model years. The smart way to do this is get gas immediately when the light comes on, see how much gas it takes to fill the tank, and subtract that from the tank capacity in the owners manual. That's how much gas you have left and it's easy to figure the mileage from there.

Of course anyone relying on that site is probably not going to fill the tank anyway.
posted by crapmatic at 6:29 AM on May 8, 2008


There's no way a Honda Civic has a three gallon reserve. I regularly put in 11-12 gallons of gas in the 13.2 gallon tank and I can't remember the last time I saw the low fuel light. Maybe it's different in other models? Mine's a 2002.
posted by sugarfish at 6:50 AM on May 8, 2008


I've never actually run out of gas, although I've come close a time or two. I'm the sort who almost never lets it get below a quarter tank, but every so often I'd forget to fill up, or be trying to wait to visit my mom and fill up at the cheap station near her house. The Mazda had about 3 gallons in the tank when the light came on, which I occasionally exploited. Three gallons in that thing, though, would rarely get me more than 60 miles.

The new ride makes literally twice the horsepower, twice the torque, and gets similar--if not better--mileage. Technology.
posted by uncleozzy at 7:00 AM on May 8, 2008


My gauge meter always assumes that when I park my car on the side of the street, I will always park it on the right side.

It gets thrown off when I park it on the left side of the road. Especially if I have 1/4 fuel left in the tank. At that point, the empty sign will light up the moment I start my car.
After a few minutes of driving, the light will go off and the needle will rise. It is as if by magic, my car is actually producing fuel instead of consuming it.

So chances are, if I where to take my car to England and drive on the left hand side, my gauge will probably indicate that I have less fuel then I actually have, simply because roads are curved and the car is banked in the oppisite direction.
posted by Timeless at 7:20 AM on May 8, 2008 [1 favorite]


I'll take this opportunity to vent a little pet peeve about my ultra-stylish and desirable Taurus: every so often, the gas gauge reading will suddenly drop down by about a quarter of a tank, stay there for a while, then creep slowly back up to what I guess is the correct, previous reading. Or maybe the low one was the correct reading and it's normally reading too high. Makes it hard to finesse the last few gallons (liters) when the tank gets low, not that I don't try. My theory is that this is a feature built in by the designers to psychologically manipulate the intended market of car rental drivers: scare them when the tank gets lowish by making it plunge to zero so they get the tank filled way before it would get low enough to visit the aforementioned damage on the fuel pump.

Or maybe I'm giving too much credit to Ford and the gas gauge is just fucked.

And Knave, thanks--I will RTFA next time.
posted by Turtles all the way down at 7:24 AM on May 8, 2008


Also, accurate measurement of a volume of liquid is tricky. Accurate measurement of a volume of liquid that is sloshing around in a tank is just crazy talk.

Not tricky at all. Just would add cost.

Interesting the number of responders who drive Honda Civics.
posted by notreally at 7:45 AM on May 8, 2008


Out-of-gas gas is the most expensive gas you can buy. Last time I went dry (about a month ago), I called AAA, and they sent a guy out who threw a gallon into the tank and then charged me $8 for it. Good enough reason to treat the 1/4 mark as the E mark and fill up a bit more often.
posted by stupidsexyFlanders at 7:49 AM on May 8, 2008


I try not to let my car get below "50 miles to empty," which unfortunately means that if you leave it unused for days on end in the summer, the fuel pump will burn out.

Stupid fuel pump, stupid bike ride home on the warmest day of the year.
posted by drezdn at 8:17 AM on May 8, 2008


I've owned many beater cars over the years, and I've learned not to trust the gas gauges. Instead, I rely on my trip odometer; Fill up the gas tank completely a couple of times and reset your trip-od to zero, figure out your average gas mileage, and then find out exactly how big your car's gas tank is. This will tell you exactly how far you can go.

In my '98 Saturn, I have a 12.8 gallon tank, I get between 35-40mpg, and the little light goes on when I've used around 11 gallons of fuel. So (depending on how I've been driving), when I get to 400 miles on the trip odometer, I should start looking for a gas station. If I haven't been paying attention, when the light comes on, I know that I should have at least another 50 miles of drive time (minimum).

I got this habit from my first motorcycle which didn't have a gas gauge at all, (you had to open the tank and eyeball it). Using this trick, I've never run out of gas, though, I've pushed to right up to the edge on a couple of occasions.

It's kind of fun that there is a community that tracks this kind of thing.
posted by quin at 10:04 AM on May 8, 2008


Top Gear once drove an Audi A6 diesel from London to Edinburgh and back again on a single tank, which impressed me.
posted by bonaldi at 10:25 AM on May 8, 2008


Timely post for me. Last night I filled up my supposedly 12-gallon tank last night with 12.214 gallons of gas. I always like to push my luck after the light comes on-- in my Civic (!) it turns on for a while, then off again for a long time, THEN on again when it means it-- but I felt kinda hardcore when that number came up on the pump.

In a previous car, I ran myself out of gas while on the road. Nothing was destroyed. Got him some more fuel and he was fine.
posted by jinjo at 11:15 AM on May 8, 2008


Also, accurate measurement of a volume of liquid is tricky. Accurate measurement of a volume of liquid that is sloshing around in a tank is just crazy talk.

Its also important to know that gas tanks are not nice regular rectangles, cylinders, or spheres. They are lumpy, misshapen things that are designed to fit in the cramped space between the trunk, the frame, and the back seat in most cars. Consequently, when the gas level drops 2 inches at the top of the tank, that may be 5 gallons of gas, but at the bottom where the tank is narrower it might only be 3 gallons. The sending units for the fuel gauges are linear (essentially dipsticks) and so do not take this discrepancy into account. So gas gauges are just approximations in the first place.
posted by TedW at 12:28 PM on May 8, 2008


(It's not all that likely, but...) For those of you measuring your tank's capacity by filling up at the gas station, be aware that you won't always get an accurate result due to gas station fraud or gas pump defects. Poorly maintained pumps sometimes dispense more or less gas than shown on the read-out.

Also, I could be wrong, but I've always assumed that no two pumps will automatically cut off (stop delivering fuel when the tank is "full") at exactly the same time. So the best you'll be able to manage using that technique would be a rough average, anyway. I'm not a mechanical engineer, though.
posted by sdodd at 12:44 PM on May 8, 2008


sdodd, yeah, when I'm measuring mileage for accuracy, I try to use the same pump on the start and end fillup, to mitigate against some of the issues.
posted by knave at 2:59 PM on May 8, 2008


I've done almost 30 miles in my Honda Civic, from the point at which the empty light came on. When the engine began misfiring, due to inadequacy of the fuel supply, I knew it was time to give up this silly experiment and pay the ludicrous motorway service station prices to get me the rest of the way home.

I drive an 07 Hybrid Civic, and when I first got it, I wondered why I couldn't even fit 10 gallons in it when the gauge was on empty. I was told that Civics historically get to empty on the gauge very early, so I started pushing it a little further, and I've found I can go nearly 100 miles after it hits empty.
posted by Stylus Happenstance at 3:07 PM on May 8, 2008


For the last six months or so that I had a car (a '92 Tempo) I used to run it so low on gas (out of sheer financial necessity) that I would have to avoid red lights going up hills because the intake was clearly in the front of the tank, and stopping on an upslope would make it stall.

I'm pretty sure I wasn't just the most broke-ass person ever, but also the lowest-gas-tank-runningest.

Fortunately now I use my feet and my bike and I never run out of either.
posted by loiseau at 5:13 PM on May 8, 2008


stupidsexyFlanders writes "Out-of-gas gas is the most expensive gas you can buy. Last time I went dry (about a month ago), I called AAA, and they sent a guy out who threw a gallon into the tank and then charged me $8 for it."

I drove a tow truck for a short time, and the people who don't have some sort of coverage like AAA typically pay upwards of $60 for that gallon. Well, really it's to have the guy in the tow truck deliver it to you. But we always carried that extra five gallons around, as that's easy money, and you'd be amazed how often it happens. You'd also be amazed at the number of people who didn't seem at all phased by the fact that they just paid someone way too much to rescue them because they forgot to check the gas gauge.
posted by krinklyfig at 6:06 PM on May 8, 2008


Speaking of filling up and gauges: I have a question about gas station pumps. At a few gas stations, when the pump stops by itself, the needle on my car's gauge is up to F (or sometimes slightly beyond). However, at most gas stations, the pump stops by itself when the gauge shows only 7/8ths of the tank full. Why is this? Why do most pumps stop so short of "full"? It's annoying. When I fill up, I want to Fill Up.

(These results are consistent regardless of time of day, time of year, or whether the engine is cold or warm.)
posted by bentley at 7:55 PM on May 8, 2008


bentley -- My guess is that it's just the way the gauge reads the amount of fuel. It takes a while for it to register tank fullness; I can't see why this would happen on the pump's end.
posted by spiderskull at 8:10 PM on May 8, 2008


I'm not sure if all cars have these, but there should be a small button next to the fuel inlet. If the pump thinks the tank is full and stops by itself, press the button for a few seconds and then start filling up again.
You should be able to squeeze in a bit more fuel and really fill your tank up.
posted by Timeless at 3:15 AM on May 9, 2008


spikerskull -- And yet it happens. I make it a point to go to the two or three stations that have pumps that fill up all the way. Every couple of months, I forget, and go to one of the other stations and, just as always, they don't fill up. I guess it's just one of those things. I thought maybe it had to do with older pumps and my older car (1998), but I never bothered to note down the variables.

Timeless -- Thanks! I'll look for that.
posted by bentley at 4:47 PM on May 10, 2008


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