I worked as a maintenance technician at a gas station for 6 years before I switched into software engineering.
Some interesting things about gas dispensers/pumps:
- What most people call a gas pump is a dispenser. The actual pump is submersed inside the underground gas tank.
- mid grade gas is just premium and regular gas that is gets mixed at the dispenser before the fuel is dispensed.
- Holding the hose up high and pulling the trigger does not allow more fuel to drain from the hose after reaching your prepaid amount
- people drive off with the nozzle still in their car surprisingly often. There is a magnetic breakaway so the hose will disconnect and not pull the dispenser over.
I can probably think of some more of people are interested
I worked as a cashier in my family's gas station for a few years. I ended up doing contract development work for a retail petroleum distributor about 15 years later.
A couple of these that I can think of:
- The temperatures in our underground storage tanks were very stable, varying only by a couple of degrees F irrespective of the air temperature.
- Fuel almost always arrives warmer than the underground temperature, so you see contraction of volume on your tank monitor as newly-dropped fuel cools.
- Gross volume is the amount dispensed into the distributor's transport trucks. Net volume is the amount dropped into the Customer's tank. Gross vs. Net and temperature adjustment factors are a place where distributors play around to eke out some margin. I wrote some code that took into account air temperature at the terminal (the "rack") where trucks were filled, along with historical rack temperatures, to produce temperature-adjusted normalized costs. When you're making fractions of a cent per gallon margin every little bit helps.
Adding to this, at least the station I worked at used the tank temperature to adjust for density changes. You were buying 1L at 20C, so in the middle of winter when the fuel was 10C, you'd get a slightly smaller volume since the density increased. And slightly more volume during summer.
Natural gas measurement is temperature-compensated, at least here in central europe. You pay for the heat energy contained in the gas, not for the net volume. The compensated heat energy is calculated based on consumption profile of the consumer class (cooking only, cooking and heating, business etc) and temperature profile of the location (pretty fine grained temperature regions).
But yes, you can still trick the meter by cooling the input medium.
One thing that threw me off in Europe is that apartments will still have individually metered water and natural gas (probably paying more in monthly account fees than usage...).
Like a cold water tap, I guess the temperature of the gas can really warm up in the pipes when it isn't run enough to get 'fresh' cold water/gas from underground quickly.
At where I live, trading water is forbidden. We rent appartments and we must not have any profit on the water. Usually, the consumption is separated per person, but sometimes that is not possible (when there are stores, for instance).
For an odd reason, however, flat rate is acceptable, so you can charge tenants a fixed monthly fee and make an actual profit out of it. Sure, there's a risk you set the flat rate price wrong.
Yeah, theoretically that would work (cooling the gas before it hits your meter). The effect would be far larger than for gasoline. Based on the ideal gas law, dropping the temperate by 20C would reduce the volume by 7% while keeping the mass of gas the same! The change in density of gasoline is only ~2% over the same temperature range.[2]
However, you'd need to warm the gas back up before burning it as furnaces are typically tuned for a specific density of gas.
Time for me to get my meter out of the sun. And shovel snow on it in winter. But I suppose the biggest gains would be during summer where the gas dwells a bit as it draws intermittently.
It would be interesting to see how much the gas temperature varies. Pipes are usually below the frost line, so pretty much the same temperature year round.
You’re right that if your meter is in the sun and it gets warm that probably warms the gas somewhat. How much, I’d be curious to know.
And I also have no idea if gas companies adjust for it at all. I assume not since most meters are pretty basic.
I think they just adjust globally. Either by adding a factor that depends on average temperatures, or a surcharge to account for 'system loss' between their central meter and the sum of all consumer meters.
GasCo doesn't care if individual customers pay the correct amount, just that they get their costs covered in aggregate.
I feel like natural gas is so cheap that any effort is worth at most $5, for a huge house with lots of people. My total bill in the summer is only $10.
I've also heard you could probably do something with magnets near your electric meter.
(I read this from some "get even with someone" book where it said to prominently put magnets on the target's electric meter for the utility guy to find)
The breakaways on the dispensers I worked with in the early 90's had shear pins and were mechanical. We lost 1 or 2 a year at our station in rural Ohio.
Funny story, I broke a plug while undoing it (there was some jank), and it refused to let me go faster than ~5mph. I needed the service station to remove the adapter.
Any vehicle with Onstar has this as an intentional feature. The feature was introduced in 2009.
Electronic ignition interlocks have been common on most vehicles over the past 20 years too... the only reason you can't remotely prevent most other cars from starting is simply software.
Thanks for helping raise awareness about these too. It’s a scary world out there when the devices people rely on can work against them on the whim of another.
Thats not a good plan - most people wont be able to transfer $5000 in 120 seconds just because it is not sitting in the cureen t account tied to your card.
It will use hacked Equifax credit reports to generate an amount that you are most likely to have with 95% confidence.
Secondly, Tesla owners tend to be more affluent. Imagine a cyberpunk world where ransomware attacks are a fact of life: buy cheap cars with reasonable security and minimise your total cost of ownership. Heh.
It is very likely that whatever you are driving today, if it was manufactured in the past two decades in Europe, North America, Brazil, Korea, or Japan, will not let you shift into Drive (automatic) without depressing the brake pedal.
And there's also universally an override to that interlock and the manual tells you exactly where it is. Usually you just pop off a little cover on the gear shift and depress a mechanical button under that cover with the key to the car or any thin enough piece of metal long enough to reach. If Tesla doesn't have something equivalent for charging cables that can be used by the owner then that's a flaw with Tesla. There's a reason why everyone else has an override.
Not the OP but the cashier at the Wendy’s drive-through pointed it out to the driver when I was a passenger. I think the passengers laughter could be measured in litre of tears.
In the UK, you can't "latch" it on - for flow, you need to hold the handle down constantly. This means that you are unlikely to drive off with the dispenser still in the car as there is no benefit to the driver to leave it in when they have finished.
It is interesting that it is the same dispenser design used around the world, but the latch is removed in the UK.
However, As a teenager I discovered the wonders of the latch on fuel dispensers on airfields. Then on the road I started using the removable fuel-cap as a wedge to the dispenser. eeeeek!
Yeees. I used to work for Diebold on ATM's, and we had some research that proved that:
- people want to take out money from the machine
- once they have their money, the activity is complete
We found that if we provided the card back before the money, they stopped leaving their card in the machine. This is because the 'activity' was taking out money.
When chip-enabled cards and ATMs first started making their way to the general public in the U.S. I had a friend who forgot his card 4 times in a single month, the last 3 times just hours after receiving a replacement in the mail. Each time he admitted that once he had the cash, he completely forgot about the card. I'm not sure if the machines beeped back then or not, but for his sake I'm glad this particular UX was adjusted.
> Holding the hose up high and pulling the trigger does not allow more fuel to drain from the hose after reaching your prepaid amount
Doesn't it though? I feel like I know this because if I don't do it, gas pours out onto the side of my car and/or the ground, when I pull the hose out.
I was once told by an electrical engineer that the whole ban on using a cell phone near a pump was due to potential interference with how the dispenser tracks how much you have pumped.
The situation is a bit complicated. From having done a moderate amount of research over years, there are basically two answers:
1) Signs that you should not use a cell phone at a gas pump are largely a result of a string of incidents in the '90s in which gas station fires occurred when the operator was using a cell phone. Causation was assumed and the warning decals were put on pumps. Later research by the Petroleum Energy Institute, an industry group, did not find any incidents that were actually caused by cell phones. The correlation may be due to a confounding factor, that people talking on cell phones are more likely to get in/out of their vehicle while pumping which could cause a static discharge. The PEI reports that, in general, improvements in vapor management in vehicles and fuel dispensers makes the risk of static discharge causing a fire low at modern gas stations.
2) General industrial best practice, and various safety regulations which are influential but not necessarily applicable to consumer gas stations, prohibit the use of electronic devices near flammable substances unless those devices are certified to be safe for that use. While many cell phones are probably "intrinsically safe" (do not involve potentials high enough to reasonably produce a spark), few are actually verified to that standard by the manufacturer (would need to be labelled "intrinsically safe" by the manufacturer following their safety analysis). In a safety-regulated environment they would thus be prohibited out of an excess of caution.
On the balance it seems likely that cell phone use at the fuel dispenser is probably not a hazard, but it never hurts to minimize distractions and extra factors when handling something potentially explosive.
I once had a stopover on a flight and was told that I was not allowed to use my phone in the plane as they where currently refueling. I am still skeptical if my phone would really be able to cause some hazard.
I don’t think that’s the main concern. I worked on offshore platforms and the devices needed to be class 1 div 2 compliant. Meaning they need to be sealed completely to avoid vapors being sparked by electrical devices. It’s a small risk, but gasoline vapor is very combustible.
What I read back when the bans were lifted around here was that cell phone use correlated with people opening the car door and rummaging around, which created a static electricity buildup, and that that was the real fire risk.
Normal tires have carbon added to the rubber to make them slightly conductive, enough to drain static.
Specialty tires like you find on drag cars do not. This is why you also see grounding straps dangling from drag cars -- to keep the driver from getting a shock when they step out after a run.
These days the filler tube on the car is made of plastic so it's less important. I did get yelled at for not putting a (plastic) fuel container on the ground "to ground it" before filling it, so the rituals persist even when the root cause has been resolved.
I had a car run really badly after filling up and had a poke about. I noticed a fluid level in the fuel pipe (it had a glass site bowl thing in the fuel line). It turned out the tank of ‘petrol’ was mostly water.
My father sold gas back in the day. He told me a story of an incident where he accidentally sold water instead of gas. When the supply tanker was filling up the underground reserves, someone forgot to close up the underground reserve. A heavy rain came overnight and water infiltrated the tank.
It was an accident. Repair costs for customers were handled through the gas station's insurance.
Water in the gasoline is an issue in stations that have above ground tanks. When the tanks are mostly empty they’re filled with air, and the changing temperature means water condenses out of the air and ends up in the gas. I used to live in a rural area with a gas station known for watery gas; if we wanted to run a chainsaw we’d get gas from farther away to avoid damage.
Keep in mind I was servicing over 75 locations and each had at least 3 tanks.
The most common way for water to get into the tanks was through the fill ports that the fuel delivery drivers filled the tanks with.
Seals could go bad, or the driver could forget to close a lid 100% of the way. Couple that with high water from rains and you’d typically get a high water alarm.
I think our system was setup to alarm if there were more than 3 or 4 gallons in a tank. These tanks are enormous. I don’t remember the capacity but they had many thousands of gallons of fuel.
Water goes to the bottom of the tank naturally and sets off an alarm. This alarm also stops the pump from running.
We’d call out a vacuum truck to pump the bottom of the tank (usually this cost A LOT of money. $1000 for 15 minutes of work)
Then we’d fix the entry point where water came in. If the alarm cleared on the system, we could turn the pump back on.
Typically the submersible tank pumps pull fuel a few inches off the bottom of the underground storage tank. You'd have to have a very high water-level for the pump to pull water.
It's pretty much gone away as a problem for cars, there's been design changes to vehicle fuel tanks, and the use of ethanol as an oxygenate means that water doesn't really build up over time (the ethanol allows the water to mix into the fuel; 'dry gas' is often just a jug of alcohol)
> - people drive off with the nozzle still in their car surprisingly often. There is a magnetic breakaway so the hose will disconnect and not pull the dispenser over.
I've done this at least once that I can remember, and maybe twice or more. Yep, the handle just popped right off. Embarrassing but fortunately not dangerous.
Any truth to the rumor that you should avoid filling your car when the main station tank is getting refilled? Think the logic was that their refilling would stir up sediment and potentially damage your car’s engine.
If you're using a dispenser that's particularly slow it's likely that the filter in the dispenser is clogged, too. At the station where I worked we stopped buying from a distributor who continually delivered "dirty" diesel fuel. Right after we took a load from them we'd see our dispensers flow rates decrease dramatically.
Fuel filters should prevent damage to the engine, but if you got a ton of gunk in the filter you might suddenly find yourself with a dead car on the side of the highway because your fuel line is clogged.
I worked with a guy that was a SFX guy for the old Walker TV series. Talking about some fun stories. He showed me a few "near misses" where the explosion was "slightly" larger than anticipated, and if you know where/when to look, you see the SFX team running for their lives in footage that made it into the edit. None of the guys I've worked with come close to the Danny McBride character in Tropic Thunder though.
I was filling up one time when the person on the opposite side of the pump drove off with the nozzle still attached. Once the end broke away, the rest of it snapped back and slammed into the other side of the pump enclosure so loudly and violently that it set off my adrenaline and I was freaked out for a good few minutes. Quite an experience!
Long time ago I read somewhere you shouldn't hold the lever all the way because it could potentially allow more oxygen through and thus have to pay just a little bit more for the same amount of fuel. Is that really true or was I being gaslighted?
What you are supposed to do is look in the Owner's Manual. It should tell you what octane number gas you should get, plus a lot more. For example, in the manual for mine (a 2006 Honda CR-V) it says this:
===========
Your vehicle is designed to operate on unleaded gasoline with a pump octane number of 87 or higher. Use of a lower octane gasoline can cause a persistent, heavy metallic rapping noise that can lead to engine damage.
We recommend using gasoline containing detergent additives that help prevent fuel system and engine deposits.
In addition, in order to maintain good performance, fuel economy, and emissions control, we strongly recommend, in areas where it is available, the use of gasoline that does NOT contain manganese-based fuel additives such as MMT.
Use of gasoline with these additives may adversely affect performance, and cause the malfunction indicator lamp on your instrument panel to come on. If this happens, contact
your authorized dealer for service.
Some gasoline today is blended with oxygenates such as ethanol or MTBE. Your vehicle is designed to operate on oxygenated gasoline containing up to 10 percent ethanol by volume and up to 15 percent MTBE by volume. Do not use gasoline containing methanol.
===========
Dealing with the octane number is easy. Just don't use gas with a lower octane than your manual calls for. You can use a higher octane if you want, but it won't really do anything other than cost more. You'll get the same performance, wear, pollution, and mileage as you would with the octane number given in your manual.
To further clarify, the average street car is designed to run on the ethanol which is sold everywhere, but some engine configurations need a higher octane fuel in order to combust the fuel completely. I had a buddy who rebuilt an engine with a compression ratio that required 91 octane, or he'd get knocking. This was during the late 80's, and more than one station around these parts had pumps selling 95 octane (it might have even been 100) for the real hot-rods.
This whole comment thread is surprising to me because I haven't seen sub-90 octane rating in ages - I have even just checked, and one of the main petrol companies in Poland sells only 95, 98, and special extra variant of 98.
> some engine configurations need a higher octane fuel in order to combust the fuel completely
This is incorrect. Higher octane ratings mean a fuel can withstand more compression before detonating. Pre-detonation, or "knocking", where an engine experiences detonation in the cylinder before top dead center can cause severe damage, so higher octane is used with higher compression engines. Lower compression engines see no benefit.
If the fuel pre-ignites, proper flame propagation will be thwarted, and the fuel will not be burned as thoroughly, leaving residue, and exhausting (albeit tiny amounts of) fuel. Sure, I put the cart in front of the horse, but I can always count on HN to point out the pedantic.
Reading this again, you're right, it was a little pedantic. This is one of those topics I feel is just rife with misinformation, so I tend to jump on explanations that don't seem correct at first glance.
I'm sure this is accounted for, but octane levels do degrade if you don't use your car often. So it can be good to put a higher octane fuel in your car.
It seems like in the US, 89, 91 are reasonable octane numbers (from reactions to this post). Around here, I've never seen stuff that low - here, it's Euro95 and Euro98. I've been told a real long time ago that the 95 and 98 in there were octane numbers.
Anyone any idea if octane numbers are calculated differently in US vs EU? Or if someone lied to me? Or if the US is really using much lower-grade petrol than is Conon in the EU?
TLDR, the US and Canada use "(R+M)/2" (also called Anti-Knock Index), and much of the rest of the world uses RON (Research Octane Number).
If you zoom in closely on the first image in my comment above, you can see that the sticker has both. It says "MIN.(R+M)/2 87 Regular" and "MIN.RON 91 Normale".
---
Tangentially, you will see lower-octane fuel in specific parts of the US. Denver, Colorado is nicknamed "the mile-high city" because its elevation is about 1 mile (1.6 km) above sea level. In many parts of the US, you will see octane ratings of around 87, 89, and 93 at the pump, but in Denver you might see 85, 87, and 91. The thinner air reduces the need for high octane.
I suppose something similar must happen in Europe, but it may not be as common or well-known. From what I can tell, non of Europe's large cities are at that high of an elevation.
Higher octanes are designed to prevent preignition of the fuel in engines that are supercharged/turbocharged or use higher compression ratios. Preignition is when the fuel combusts before the cylinder is at the "ready" point in its cycle (wherever that is for your car, with variable timing and all that).
As others have said, your manual will tell you, but a good rule of thumb is if you don't have a high performance vehicle or an engine with a turbo or supercharger, 87 should be fine.
Higher octane means the gas has a better ability to resist knocking, which is spurious ignition not caused by the spark plug. Knocking can damage your engine if it happens often. Turbocharged cars have a higher tendency to knock, so they generally need high-octane gas. If you put low-octane in a turbocharged car, most modern engines will detect the knocking and detune the engine automatically to prevent damage, but that means you're not getting the power or efficiency the car was designed for.
So use high-octane in turbocharged cars and low octane for non-turbocharged cars. (If you use too high an octane in your car, it won't hurt anything but your wallet.)
If you're racing a turbo car you might need close to 100 octane, which cannot easily be bought but it can be made by adding toluene to your gas tank (google it).
Some states have different levels. In Colorado 85 is common. I assume it has something to do with the air pressure and oxygen content of the air perhaps?
One of the reasons for this is that for a NA (normally aspirated) engine, i.e. not turbo charged or super charged, the lower atmospheric pressure results in a lower compressed pressure (versus sea level) as the piston rises toward the top, which means a lesser chance of pre-mature detonation (knock) due to pressure, which is what higher octane prevents. So therefore you don't need as high octane at higher altitudes.
Unfortunately that isn't true with turbo or super charged engines, which are more and more popular. I really miss the 93 (and even 95) octane fuel I could get in Boston. I use a octane booster in my car here in Colorado to help offset the lower octane pump gas, and allow my turbo charged engine to make more power (by not having to pull timing to accommodate the lower octane gas).
85 is functional at elevation, but definitely still not preferable at elevation.
Works best with carbureted engines, which are obviously few and far between these days. You shouldn't put 85 octane in a modern fuel injected engine period.
The method of fuel metering the car uses does not necessarily have any connection with what octane you should use. It's all about the engine design. If we are going after rules of thumb, I would say that if the car is turbocharged, it will most definitely run better with higher octane. Although my turbo VW can run with regular fuel, it will just change timing and make less power.
I have a 78 Fiat with a carburetor however, that definitely needs 91 or higher.
VW is seemingly, in my experience, an outlier. Their small displacement turbocharged engines will run fine on 87, but really like 91 (or E-15 88). My '14 Jetta with the 1.8T got better power and fuel economy on "the good stuff."
> mid grade gas is just premium and regular gas that is gets mixed
There is nothing else "premium" about premium gas, than that it can be compressed more in the engine. Compressibility is measured by the octane rating, so it makes sense than mixing 87 octane gas and 91 octane gas, gives you 89 octane gas (using the American octane scale, Europe uses a different scale).
At what point in the distribution chain is ethanol added? I prefer to run ethanol-free fuel when possible, but would also prefer to use fuel with good detergent additives. I've always wondered if the gas at the local ethanol-free station is missing the additive package as well.
Does anyone still use above-ground tanks? Just wondering if there's any truth to buying gas in bulk during cold weather for density reasons.
(though I'd imagine the price/barrel has been fluctuating more than the temperature would cause lately)
As I understand it, petroleum companies provide "winter mixes" of fuel that accommodate for the difference in density, so there isn't a real advantage to this.
Above-ground tanks can be appreciably cheaper, mostly due to increased inspection and maintenance requirements for underground tanks due to a history of leakage problems. That said, the price difference isn't big enough to justify the use of space (especially considering setback requirements) in urban environments. You will still find above ground tanks in newer gas stations in rural environments, though.
From what I heard, pretty much all gasoline starts off the same in the US, the brands will add a tiny amount of their own detergent on top of what's already in the base. Seems plausible.
There are many different blends of gas, and refineries change with the weather (winter fuel mix evaporates faster than summer mix, and will not need summer emissions). Gas stations often choose their own mix of detergents/additives, but otherwise all fuel in a town comes from the same refinery with the same contents.
Most stations just go with the refinery default additive mix, which is typically pretty good. Some national brands go with a slightly better additive mix. Some national brands go with a cheaper additive package. You need to be a large chain to afford to pay a chemist to design an additive mix though, so the majority of stations don't.
According to https://en.wikipedia.org/wiki/Top_Tier_Detergent_Gasoline you're getting at least the EPA minimum amount of detergent additives even in low-octane fuel, and many brands participate in the Top Tier standard that requires even more additives, again with the requirements applying even to low-octane fuel. So I wouldn't bother paying extra for premium fuel for the sake of additives when the higher octane rating isn't needed. Which gas station you go to will probably affect that more than which grade of fuel you select at the pump.
There is generally one refinery that all stations in a given town buy from. Shipping fuel from a different refinery would be enough more expensive that you wouldn't be competitive.
Sometimes stations have their own additive package.
You're getting them anyway, but sure in the sense that you're getting part-premium. I don't know many, if any in the US, that have actual USTs full of midgrade and don't blend the two more common ones at the dispenser.
Priming has nothing to do with cleaning. It’s higher octane fuel. If your car Isn’t designed for higher octane fuel it will run like garbage. The whole point of high octane fuel is that it requires a higher temperature to ignite. If your car Isn’t designed for it it’s most likely only going to partially burn the fuel.
No, the main point of high octane fuel is to be resistant to higher compression ratios so it doesn’t pre-detonate. Spark plugs have no issues igniting it.
What op is referring to is additives that are added in by some gas dealers to the high octane fuel to upsell you. “Techron” is one I recall seeing at Chevron IIRC.
High-octane fuels will not burn poorly. It just isn't necessary to increase octane further once the threshold of knocking/self-ignition at the target compression and cylinder temperature is reached.
Plus you missed the point: In many places the premium fuel is the same octane number as regular (e.g. 95), but premium is with additives for <insert vague marketing>.
I think it's the same as the relationships between the octane numbers you see. So if the pump as 87, 89, and 91 grades, then the mid-grade will be a 50/50 mix (ratio 1:1) of the 87- and 91-octane fuel. If the grades are, say, 87, 89, and 93; then the ratio would be closer to 2:1 of regular:premium to get to that mid-grade.
Only reason I know this is because premium gas in California used to be 92 octane. So the three choices were 87, 89, and 92. When we dropped to 91 octane, a lot of the stations near me had to swap out the yellow sticker on their mid-grades to read "88.5". That was my clue that the ratio had not been adjusted yet.
Only if your vehicle requires hit. Premium gas is rated for higher compression (generally turbo or supercharged engines). If your owner's manual doesn't recommend a particular octane, just get regular.
With turbos and computer adjustment of timing and everything, it's more plausible than it used to be that premium will give you more power. On the other hand, it's also more likely that a lower grade will not damage your engine even if premium is recommended.
Hands down the most fascinating part of this thread is the number of comments from people saying "in the US x is different" or "in State y it works this way". You go on reading and you see people contradicting each other because of course, different States, different solutions; different towns, different solutions.
It goes to show how much people think they know their country, to what degree they believe to know everything there is to know about their culture, history, and surroundings. Really though, we know very little despite what we tell ourselves or others.
I guess the message is: travel a little people. Even if it's just to the neighboring State for crying out loud.
I used to be puzzled by how anyone could ever drive off with the nozzle still in the car. I had only seen the non-latching dispenser, and service stations don't exist in my country. I was probably (shamefully) thinking something along the lines of "dumb Americans."
Once in the US, I realized it's a mixture of full service and self-service stations with latching or non-latching dispensers, depending on the region. And I do need to make an extra glance at the gas tank door before driving off.
They made an exception for late-night now, to allow stations to staff just a single attendant who can stay in the store, while people gasp pump their own ultra-flammable danger fuel!
I'm from a self-serve state and full-serve weirds me out, so when I was in Portland I found myself driving up into WA to gas up my rental.
That's good to know. On a late night road trip up to Mt Hood I got chewed out by the attendant for touching the machine. I imagine a to. Of Californians make that mistake.
One of the low-key weirdest things about moving from California to Ontario, Canada was that, until earlier this summer, basically no gas stations ("gas bars") had the auto-shutoff triggers. They seemed to make a lot more sense here in the land of actual winters than in Oakland, but eh.
Interesting gas pump related differences between Germany and the US:
- German gas pumps are mandated to have a vapor recovery system, which sucks out the poisonous air vapors from the tank as it is being displaced by new gas. US pumps don't appear to be mandated to have such a system, but many still seem to have it. They also often have some kind of plastic or rubber seal behind the tip of the nozzle that prevents gases from escaping the fuel tank - irritatingly, this seal, which I consider a great and practical idea, is almost unheard of at German gas pumps, even though they are mandated by law to perform vapor recovery, and one would think that such a seal would help with that.
- The notion of pre-paid gas is almost nonexistent in Germany, and doing pre-paid gas purchases - including doing the dance of having to walk to the shop assistant twice or estimating the remaining space in the tank and only filling it up partially - are a typical "weird thing" German travelers encounter when they do their first US road trip.
Pumps here in Germany usually don't even seem to have the capability to slow down fuel pumping when the money runs out, nor can they completely shut off the flow. There are a few modern pumps that can do this, they allow you to pre-select an amount (that you don't have to pre-pay, the pre-selection is just a convenience thing for the customer), but most of them can't. There are a few automated, unmanned gas stations where you "kind of pre-pay" the fuel by placing a hold on your credit card, then fill up, and finally you complete the purchase at which point the account is charged the amount you purchased. But the size of the hold is usually high enough to cover even the largest cars' fuel tank to be completely filled, so it is untypical to hit that limit. Because of this, I don't even know what happens then with regard of the fuel flow: whether it actually stops (because of the aforementioned technical inability of most of the pumps in Germany to stop at a precisely predeterminable dispensed amount, implementing that might not be so easy) or whether it just lets you run past the limit and sorts out potential fraudsters later (by involving law enforcement and identification of the customer via the credit/debit card).
- Switching between different kinds of gas (octane differences, or premium fuels) is usually done by taking a different hose from a rack of 4-6 hoses + nozzles attached to the same pump. The US-typical switches you need to press to choose your fuel type are inexistent in Germany. These have also been a major hiccup source for first-time US road trippers in my circle of friends: "Why doesn't the gas flow? I've done everything right...ah, I need to choose which gas I want first!"
It didn’t really occur to me until reading a lot of messages in this thread, but I realized how normal it used to be one going to a gas station to enter the shop to pay in cash. I remember as a kid whenever we went to a gas station my dad would always be careful he goosing the trigger of the gas pump to line up the decimal point on the rolling dial. That was just part of going to a gas station. You basically walked in put down a 2 $20 bills and said “40 on three“ for example. For you millennials, this meant put $40 on pump number three. But let’s say your tank only took 35-ish dollars in gas. Well you didn’t wanna be left with spare change, so you always just squeeze the trigger just enough until the meter read and even dollar figure.
For the first decade of my driving life that’s how I did it as well. But that now seems to be such a distant memory as I am 100% of the time just paying with a credit card at the pump.
The "40 on three" thing is something I got very used to during US road trips, because most US pumps didn't accept foreign credit cards in order to pay at the pump. I tried it a few times, it basically only worked on one or two out of ten. The other eight or so asked for a Zip code to be entered, and regardless of what I entered - my real German zip code, a US zip code from the vicinity of the pump, all zeroes - the pump refused it. I could use my credit cards to fill up by going to the shop, handing it to the clerk asking her/him to authorize a certain pump, which they would usually do as long as they were allowed to keep the card in their possession until I filled up. Then after filling I would have to retrieve my credit card, which would then be billed with the exact amount I bought.
All in all a very inconvenient process, and I had to explain it to some clerks because they weren't used to it due to the locals all being able to just pay at the pump if they wanted to use a credit card. I quickly switched to just getting a stash of $10 and $20 bills from an ATM, estimating whether I could fit $20 or $30 worth of gas into the vehicle and pre-paying that amount, leaving a bit of space in the tank for the convenience of not having to walk into the store a second time.
In the US you'll find the vapor recovery boots in California for sure. Other locations too, depending on the state & local laws.
Paying before pumping became a thing when gas went to $4 a gallon several years ago. Stations had a lot of people driving away without paying and the amount stolen was below what the police would investigate.
You can often pay at the pump, and they way they work is they authorize a certain amount ($75, I think) against your card, and then when the station settles at the end of the day, the actual amount will be applied. I have exceeded American Express's hold limit a couple of times during cross-country drives, and had to talk to their fraud department..
Pumps with one hose are cheaper. You'll probably get a dribble of whatever grade the previous customer chose from what was left in the hose. But diesel will always have it's own hose.
The funny thing about precisely stopping the pump - prices in the US seem to always have 9 tenths of a cent added to them - like $2.599 per gallon. If you purchase exactly one gallon, and hand over $2.60, there's no way to get that tenth of a cent change. I expect it was originally a marketing thing, and now it's a custom.
Having done a lot of traveling along with a lot of reading (often at the same time), just reading about a place is a good start, but there's no substitute for actually going there, meeting real people, eating the food, dealing with public transportation and the weather, experiencing all the tiny inconveniences and innovations that shape life. It broadens your worldview, confirming beyond a doubt that the way things are done in your town is neither the only nor the best way, just one of many, and that the people who live "over there" are in fact people, not just statistics.
I agree that the environmental impact is a big problem. But perhaps if more people traveled, we would be more likely to get the kind of international cooperation we need to tackle climate change systemically.
Nope. Having traveled a bunch myself and talked to many other people who have traveled, traveling to a place can easily be one of the worst ways to actually learn about how the people live. Being a tourist in a place teaches you nothing about the voting process there, the community councils, the property tax codes, etc.
Essentially, traveling to another place without living there for many months only gives you an understanding of the most superficial aspects of life.
> we would be more likely to get the kind of international cooperation we need to tackle climate change systemically
This doesn’t even make sense. People who live in the same cities struggle to cooperate on even super local problems like housing. Ted from Kansas City flying to Europe to eat a steak in Florence is not going to help anything.
Bending over backwards for the enrionment at the cost of living life is paperclip maximizing - the point of maintaining the environment is to keep it sustainable for our wants and needs.
One of my favorite pictures on wikipedia is of the original Ferris Wheel from the 1893 Chicago World's Fair. It's enormous. Each car is the size of a small house. Opens one's eyes to what mankind was capable of even in 1893.
Funny, I found myself asking this question recently too. Also, who made them.. I wish some of these industrial everyday products had the name of the designer attached. Found a video which has a nice nozzle teardown [1].
Another interesting thing is the story of self-fueling, an study in slow adoption. Apparently, the current state of affairs was reached by 1980s or so [2].
I remember driving from California to Oregon, getting to a gas station and trying to pump my own gas... the clerk almost jumped to my neck (in my memories at least :-p).
Thanks for this, I'm always amused at how certain phrases and sayings get twisted-up a bit during translations between languages, but I'm sure you actually meant "jumped down my throat"...
That "jumped to my neck" threw me for a loop! Once I saw you point out the proper idiom I was able to breathe easily again. I've tried to find the origin of this idiom, but I've come up dry as a bone.
It's strange, but I come across these idioms from other cultures back-to-back as I read stories on HN. That's most likely due to the blood, sweat, and tears people put into communicatng on here. Or, maybe language is a bone of contention, and the idioms are simply a breath of fresh air that grabs us by the nape. Whatever the cause, the languages differences sometimes chill me to the bone, maybe they even cause a gut feeling as they hit a raw nerve.
I suppose it's better to be up your ears in idioms, rather than waiting with bated breath.
Until now, I had been unaware of the earliest usage shown below, and I had always understood the boxing reference to be the origin. Live and Learn!
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To be “thrown for a loop” or “knocked for a loop” refers to being bewildered, dazzled, disoriented and shocked by some event (“AT&T and T-Mobile were thrown for a loop last week when the Department of Justice sued to block AT&T’s planned acquisition of T-Mobile,” CNET, 9/5/11). The phrase first appeared in print in the 1920s, and comes from what the Oxford English Dictionary terms “a centrifugal railway,” but which is, no doubt, better known as a “roller coaster.” The “loop” on roller coaster runs is the point where the coaster arcs upward through a complete circle, leaving passengers upside down at its apex. The term was initially used in the literal roller coaster sense and then to describe aerobatic maneuvers by pilots “looping the loop,” and finally in boxing to mean a powerful punch that downed an opponent, before acquiring its modern “OMG!” usage.
I've also heard it as "knock me for a loop", and I think it calls back to "feeling loopy" as a sort of "dizzy", so to throw/knock someone for a loop is to metaphorically hit them so hard as to make them dizzy or disoriented.
In Italian "saltare al collo" (literally "jump to the neck") can be used to mean a form of physical aggression (but normally used metaphorically) in English it would be more like "grab by the throat", I believe.
Viceversa to "grab by the throat" translates literally to "prendere per la gola" that actually means to "Tempt through food".
Don't know what's their native tongue but at least in Portuguese we have a saying that would translate literally to "jumped to my neck". I also love these language things :)
These days I arrange my fill-ups to avoid New Jersey. Last time I stopped there, I had to haggle with the guy to put the last 4 gallons in my 12-gallon tank, because the wonky fuel neck would trip the auto-shutoff prematurely and he thought it was done. I knew how much fuel I'd burned and I could look at the counter and know it wasn't done, but Professor Petroleum was having none of it.
I don't care what the idea is, it's annoying, insulting, and backwards.
It used to be commonplace to tip gas station attendants everywhere in the US back when boomers were growing up; full-service was the norm and the attendants would check your oil and clean your windows.
Me, from out of state: "I'd like to pump my own gas, please". In other words, I do not want some stranger accidentally dousing my bike with gas or scratching the tank.
Enjoyed that youtube explanation (3 minutes, clear explanation). Just a comment to encourage later readers to follow the link, if they were on the brink of doing so.
Doesn't always shutoff! I was filling up one of my cars a year or two ago, watching the meter tick up and up and up so not watching the pump handle/nozzle itself, just cursing the price of a full tank etc.
Someone in the car behind actually jumped out and came over to let me know that my tank was overflowing and going all over the floor.
Honestly, I do. My usual routine is to open the fuel hatch, check for card skimmers, swipe my card, punch in my phone number for the loyalty program (if I'm at my usual gas station), punch in my ZIP, grab the nozzle, select a grade, stick the nozzle in the hole, set the trigger on the lower speed, head into the store, buy beer, put the beer in the car, wait for the pump to finish (if somehow it hasn't), put the nozzle back, close the fuel hatch, and drive off on my merry way.
This all seems to be pretty normal where I'm from.
A word of warning, all that moving around is potentially† building up a nice static charge on your body just in time for you to discharge it through the cloud of gasoline fumes as your hand closes around the trigger to unlatch it, with well-documented pyrotechnic results.
This isn't a theoretical concern: there are numerous documented cases, even multiple instances with footage on <popular video sharing website>, so a notion of "this can't happen" argued from first principles isn't just moot, it is potentially harmful.
The proper safety advice is that if you've been moving around, ground yourself by contact with some other earthbound metal before approaching the nozzle.
i never said it cannot happen. the fact that there are a few videos of this happening somewhere doesnt refute my point that the probability is still nearly zero; if this was not the case, people would not be allowed to fill their own tanks due to the enormous liability.
i'm certain more fires happen from people plugging in frayed cables into 120vac outlets without first checking the whole length of the cable, but i would not tell everyone to perform this thorough investigation before plugging in every device.
I didn’t take away anything probabilistic from your earlier remark, so I’ll take this followup as an amendment.
Actually, though, I do recommend that you inspect mains power cabling & connectors prior to installation and on a regular basis subsequently. Having received a mains shock from improperly installed amplification equipment it is not something I’d wish on anybody, and it is completely preventable.
As for people not being permitted to latch the fuel trigger, a quick read through the comments here and passim reveals that many jurisdictions do have significant restrictions on self service as part of the operating license for retail fuel outlets, including removing the trigger latch pin, or mandatory pump shut-off if folks are observed using a mobile phone, having a smoke etc. That last one is astounding but some people are just fucking stupid, who knew?
In general I try to avoid circumstances that have even a low probably of ending in self-immolation, electrocution etc and will happily follow (and recommend) basic and simple protocols to reduce that likelihood further.
But then, I’m one of those crazies that looks both ways before crossing the road, wears a bike helmet, gets a professional to pack his reserve etc. This year I even learned to wash my hands.
> But then, I’m one of those crazies that looks both ways before crossing the road, wears a bike helmet, gets a professional to pack his reserve etc. This year I even learned to wash my hands.
all the things listed here are actually a few orders of magnitude more reasonable, statistically speaking.
I've seen similar stories before, and I'm wondering whether (some?) US pumps might work slower than ours? Or maybe it is just larger fuel tanks due to larger cars...
Here in Finland typical pumps fuel 40 litres/min, i.e. 10.6 US gallons per minute, which gets my car from near-empty to full in just over a minute.
It definitely depends on the gas station. Some pump faster and some pump slower. 10 gal/min sounds about average.
I like pumping at truck stops (Flying J, Loves, etc) because they tend to have faster pumps.
I drive a pickup truck with a 38 gallon (145 liter) tank. So I definitely notice slow pumps and seek out gas stations with faster ones. I have been to many gas stations where they pump way too slow and I will just get a few gallons and leave because I don't want to sit around all day while it fills up and I don't trust the auto-shutoffs enough to leave it unattended. I have had one fail once and luckily was there to stop it before too big of a mess was made.
I am lucky enough to live right next to a Gasoline Distribution company and they have a really nice public gas pump that you can use with super fast pumps and all of their gas is ethanol free (most gas in the US has ~10% ethanol). So that is where I usually fill up.
ZIP code verification is commonly used for credit card authentication at gas pumps in the US, especially before the advent of chip & PIN.
This is immensely annoying for Canadians who drive their cars to the US, although there are some built-in workarounds supported by the credit card processor such as punching in the 3 numerical digits of a Canadian postal code followed by 00.
When credit card companies started requiring pin&chip at stores in the US a couple of years ago, there was a special exception for gas stations, I guess because their pumps are a pain to retrofit or something. As a result, it’s an easier target for fraud.
I'm from Norway. Zip code thing completely threw me off first time I was renting a car in the US. Drove up to the pump, whipped out my card and... what? Why on earth do they need to know my zip code?
Didn't know any zip codes offhand so ended up paying inside, which turned out I had to do in advance of course, another aha moment. Inside the cashier naturally asked how many gallons I wanted. I had no idea. Rental car was not one I'd ever driven before, and I hadn't looked in the manual for the size of the tank. I took some comfort that the cashier had no idea either. And so there I was trying to guess how many liters the car's tank might be, how much might be left and converting that into gallons.
Back outside with a conservative 4 gallons to pump, the guy behind in line kindly informed us of the zip code of the area we were in, for next time. Came in very handy.
90210 is the most famous zip code in America because there was a really popular show in the 90s that referenced that zip code called "Beverly Hills, 90210" (commonly known as just "90210"). It had various spinoffs going into the 2010s.
Because that zip code was so famous an unrelated reality show was named "Dr. 90210" about plastic surgeons in the Beverly Hills area.
I don't think the area you were in had anything to do with it. The zip code is supposed to match the card.
And you don't have to guess the exact amount of fuel, you just pick a number greater than the cost of a fill-up and less than infinity/your credit limit.
Yeah that I gathered, but the closest thing to a zip code we got here in Norway is four digits, and it didn't accept that.
> you don't have to guess the exact amount of fuel
Of course, but the cashier forgot to mention that I'd get back what I didn't use, and being a bit off balance already by the new experiences I didn't think of this myself.
I believe it's a US credit card thing. Not sure if anything actually checks the zip code nowadays. A long time ago, I almost got stranded in the US with my (European) credit card, and I suspect it had to do with not being able to provide a fitting zip code (different formats).
As others said, but more specifically, requiring billing zip code to match what's on file for the credit card can significantly reduce fraud, and that impacts the processing fees. Some merchant accounts may charge less if the billing zip code matches, some accounts might not have a difference in charges and may even actually charge a fee to do the address verification, but the reduction in chargebacks could be meaningful.
Are you a fellow Texan? Because this sounds like Texas. Nothing wrong with grabbing a little BBQ sammy from Bucee’s (or a cake ball of course) whilst the fuel flows around them parts.
Nevadan, but same concept. Hard to beat Maverik's burritos and a Monster in the morning :)
My hometown's local gas station (out in the boonies in California's Central Valley) renovated and now has a full-blown burrito shop, and they're probably the second-best burritos I've tasted. Always a treat whenever I'm visiting family.
The downsides to automation. More often than not, even if you are 90% of the time alert, you get fairly comfortable and not watching.
I do watch my car while i am doing some other stuff or looking at my phone, but seen some other automation related stuff that makes me lazy. Like not locking the door at home when going out, because it's automatic.
I was watching the price going up on the display, and not the actual hole in the side of the car where the fuel goes in.
For UK pumps you actually need to stand there and physically hold the pump nozzle the whole time. If you let go it is spring loaded and it stops pumping.
Of course, you don't have to look right at it while it is pumping...
That's caused by the mechanism described in the article. If you squeeze the handle hard you get a fast flow. This can cause the gas to splash back into the nozzle and cuts off the flow because it appears that the tank is full.
You cant do that in most European countries as the trigger will need to remain engaged for the valve to stay open. So you just stand there holding the pump handle bored the entire time. I get its more safe but I wish we had the same system as they do in the US
There’s usually a little latch on the handle that you can engage so that the valve stays open and you can let go then. No need to keep glued to the pump, even in Europe.
You should still watch the pump though - you’re handling flammable substances.
People seem to do it all the time in California at least. I've never actually seen a tank overflow but if it did it seems like the potential consequences could be disasterous.
Maybe they should remove those flip-up latches if they want to prevent people from doing that.
Yes, I've done this my whole life and seen many (most?) others do it too. I've never even seen thought it's a bad idea, because the gas pump shut off has worked 100% of the time for me.
Go to a gas station, start pumping, and lock it, then go inside the gas station to buy some snacks. When I come back outside, the gas is full and I can go on my way.
I’ve done this hundreds if not thousands of times and it only didn’t work once, for the first time, a few months ago when I was filling my UHaul in Queens to move out of New York City. It was fitting.
One of my old coworkers used to totally and completely trust the auto shutoff. To the point that he didn't even stop the pump before pulling it out of the car. He would just yank the still running pump out and it would shut off. One day he comes in to work complaining about how the pump he used the day before didn't work and he got covered in gasoline.
We all just looked at him incredulously when he explained what happened.
I had an incident where a customer told me "they spilled some gas". I go out to see ~20 gallons of gasoline on the ground (my best estimate - was a puddle about 16 ft x 6 ft x 1/2 inch deep)".
They were filling a huge motorhome, so it would take a while to fill regardless and they weren't paying attention.
I should have called the fire department, but was a dumb teenager working alone. Threw a few buckets of absorbent on it. It was over 90F that day and windy, so it took 10 min for most of it to evaporate.
The design uses a vacuum to trip the shutoff, and that's created by the liquid moving through the venturi, so one of the things that can cause it to not work, besides wear and damage, is if the liquid is moving too slow to generate enough vacuum to actuate the mechanism.
Haha, same happened to me in Spain two years ago. I stood there minding my own business like a doof until someone on the other pump were like, "Yo!! Watch out". Wasn't much, but still surprising.
This happens to me sometimes, too, though I drive a 1985 VW van. It seems to be related to the nozzle fit and holding it very firmly, but I find that today's pumps are pretty heavy, require a very firm squeeze, and are hard to hold just right. Maybe it's just an Oregon thing, where we are not allowed to pump our own gas. I've had licenses in four other states and gassed up myself plenty of times. Whenever I'm in Washington or other states with my van, I tend to let the auto-hold engage.
I don’t understand: If we use the Venturi effect, that means we’re pulling air and mixing it with gasoline.
Are we really pre-mixing air+gasoline into the tank? Isn’t that a much higher risk of sudden explosion, compared to a tank with only carburant and no comburant?
The claim about Bernoulli effect would be flat out wrong. Moving fluid that has been pumped into motion doesn’t normally have lower pressure than the ambient pressure (i.e. exit pressure). Wikipedia better explains it - they’re using a venturi pump - i.e. there is a construction in the tube that causes the fluid to have faster speed and lower pressure than the exit.
Now, whether this pressure drop causes underpressure is another matter and depends on whether the effect is stronger than possitive pressures in the system relative to your point of reference (for example, outside atmospheric pressure).
For example, there might be obstruction downstream which means there is already positive pressure in the pipe so the pressure drop from Bernoulli effect is lower than the positive pressure and you still get overpressure (Bernoulli effect is rather weak at slow speeds as it is proportional to square of the velocity of liquid in the pipe).
So, in general, when you have fast flow through a pipe, a hole in the pipe might cause the water to flow out but it could also be sucking air in. It all depends on whether positive pressure is stronger than the effect.
Yes, that is all true. More specifically though, in the particular system we're talking about, gasoline flowing through the main nozzle (which has the same diameter up to the exit) has essentially the same pressure as the ambient pressure. There is an obstruction downstream past the nozzle known as the "splash" which is responsible for bringing the liquid's velocity to zero.
The linked article invoked the Bernoulli effect to compare the pressure of the pumped gasoline in the pipe to the pressure of the ambient air; the Bernoulli effect is based on conservation of energy and does not apply here because the pumped fuel is not magically transforming into ambient air in an energy conserved way.
This is incorrect, moving fluid always has lower pressure, you don’t need the narrowing of the venturi to get suction, it just works better when you do.
An intuitive way to think about it is to set up a straight tube with a fan at one end, open on the other end, with a small hole drilled somewhere in the side.
With the fan off, clearly the pressure is the same everywhere.
With the fan on though, air moves out the open end. That moving air has to stop once it is out of the tube, that resistance to the moving air at the end of the tube is dynamic pressure. The hole in the side though has no moving air directed at it, not having to resist that moving air, the pressure is less at that interface than at exit.
If this wasn’t true, you would have to be compressing the air, that is increasing its density. Saying a fluid is incompressible is equivalent to saying the speed of sound in it is infinite; that is obviously never true, however the effects of compressibility are relative to the speed of sound so as long as you aren’t dealing with flow of hundreds of miles per hour in air, incompressability is a very accurate approximation.
In your particular example, the air in the tube would be at slightly higher pressure than ambient, and because it doesn't have much surface tension (unlike gasoline) would slightly leak out of the hole on the side as well.
In normal conditions fluid has lower pressure if:
(a) it was flowing and is now moving faster because of a geometric constriction
(b) it is being sucked (i.e. being pulled into a lower pressure region than ambient)
Moving fluid has higher pressure if:
(c) it was flowing but isn't flowing as fast due to a geometric expansion
(d) it was pushed (i.e. coming from a higher pressure area than ambient)
Note that in the case of a fan in a tube, the fluid has lower pressure than ambient behind the fan, and higher pressure than ambient after the fan.
I have a 2008 Prius and the gas pump repeatedly "shuts itself off" due to a faulty mechanism within the gas tank. Certain pumps are too high pressure and they trip the shut-off very easily, other pumps if I hold it at just the right angle, the gas will flow through. It's super tough on some pumps, it took me 30+ tries to get it to continue flowing at the last fill-up.
Seems likely you've got a defective (crimped, bent, or obstructed with eg. a bit of a rag) fuel filler neck.
The mechanism in the pump depends on a free flowing, successfully venting filler neck. If a bit of detritus got into yours and is reducing the flow, it will do exactly that. Seems more likely than that every pump handle you visit is defective...either that or the small gas tank/bladder on your Prius can't accept a high enough flow rate to work with normal pumps, though I'd be surprised if Toyota missed that.
Dropping the tank and replacing it or the filler neck is a pretty easy DIY project.
My old car's charcoal evap canister had turned solid after 20 years. This would cause pressure buildup in the tank that would trigger the shut-off when putting gas in. It was really frustrating just adding $5.
This also illuminated the SES light and, more importantly, would have resulted in a failed emissions test. Instead of spending $250 on a new one I hit the old canister with a hammer to break up the charcoal and it was all good.
SRS light is for the Supplementary Restraint System (airbags and seatbelt pretensioners) so unlikely to be related to the filter. Might trip the MIL/Check engine light though!
Probably not the Safety Restraint System (SRS) light. Perhaps the Service Engine Soon (SES) light, which is often the same as the Check Engine Light (CEL).
The hammer idea is new to me. I spent several years working on cars and still like to wrench on the side.
Another poster mentioned it's a good idea to check your evap canister. Also a good idea to check your evap canister purge and vent solenoid valves. If the vent valve is sticking closed you'll get positive pressure in the fuel tank during fueling that tends to trip the filler shutoff.
Do you think it's about the car? Because I also occasionally encounter a gas pump that automatically shuts off while the tank is still empty. I don't see how the car has any influence on that, so I assumed it's the pump. But as it happens, I think my Prius is also from 2008.
It's the interaction between the dispenser and the car. I've driven a few vehicles that would have trouble at some dispensers. With my vehicles, I was able to make it usually work by holding the handle up a little and avoiding stations with dispensers that didn't get along with my vehicle.
It seemed to me that sometimes the angles would mean the gas splashed off the filler tube in the wrong way and confused the dispenser. There's a bunch of different ways to run a filler tube, and different dispenser handles, so I adapt.
In my case, my first vehicle was older than me, so you don't exactly complain to the manufacturer that it has trouble filling at some stations. When newer vehicles acted the same way, I already knew how to jiggle the handle to fill up, so I just wouldn't get to wash my windows at the same time as I filled up, if I went to the wrong station. I wasn't ever one to buy stuff inside while the vehicle was filling, so not a big loss of functionality.
About 1/4 the time the pump is either shutting off every 5 seconds or doesn’t shut off. But luckily there’s a subtle but obvious sound of the tank being almost full and I’m standing right there.
Also, if you know the capacity and the current level, it’s easy to figure how much it should take to fill. I rarely fill to the brim anyway, only on a long trip.
I sat next to a guy in the petrol pump business once on a flight from a time before time (pre-COVID), so I asked him how the pump knew when to stop: he explained that the handle contained a rotating cylinder (halved in the middle) with a known volume V that rotated N times until V*N = Purchased Liters.
I've been reading The Straight Dope at least intermittently since the mid 80s. It's been a wonderful source of esoteric trivia and it's finally come to an end. There might be something taking its place but for now it's over. https://www.straightdope.com/21374450/a-note-from-cecil-adam...
I bought a car ~7 years ago in Illinois and transported it to California. Pumps in IL worked fine with the car, but upon arriving in CA, I found that gas pumps will prematurely shut off, almost immediately upon pumping, regardless of how empty the tank is. In order to prevent the premature shutoff, I have to lift the pump hose at about a 45 degree while pumping.
Any idea what's going wrong here? Is it my car or the pump? Is there a difference between the pumps in IL vs CA?
I have a Chevy truck that does this. Purchased and used in California. I think it's just a subtle mismatch between the gas port and the overly complicated vapor reclamation devices that are on California gas pumps.
CA requires vapor capture systems on their nozzles. The don't fit very well over the gas inlet and cause the nozzle to sit a little weird. In my experience just pushing the nozzle in, and pulling it up slightly fixes the issue. I have had this issue on a Mustang and a Prius.
I once filled up at a station in NJ where the attendants had disabled the spring for the self locking latch. Not a huge issue for a car filled from the side but with the nozzle pointing down into a motorcycle tank it locked itself without my knowledge and then I couldn't get it to shut off while gas was spewing all over the bike. Still alive though.
NJ has been a full-service only state since forever. IIR, Oregon is the only other state like this. Funny thing is, NJ has had cheaper gas (10-15% cheaper than neighboring NY stations where its universally self-service and a cashier. Yet somehow the NJ stations can afford an employee, the HR costs and still turn a profit for someone else.
Yeah, the exact figures escape me but essentially having someone on site to cleanup, watch things, etc costs less than having no one... which is one of the reasons Oregon mandates it, it provides jobs and has zero effect on the profitability of the service station.
I'm a New Jerseyan and I like our full-service gas since it reduces spillage, but if it were actually cheaper to have an attendant, wouldn't every station nationwide have one by now?
That is exactly the reason. I live in PA. NJ has higher income taxes than PA but lower gasoline taxes. This changed in recent years as gasoline taxes in NJ have gone up, eliminating most of the advantage of filling up there from people on the NJ border.
YMMV but when I was touring the east coast the attendant handled the payment but I did the pumping. My preference anyways, you have to actually care if you want to keep the fuel off your paint.
There is a safety issue with fires caused by static electricity. This is most often seen with women wearing synthetic clothing who get back into the vehicle in the winter and then get a fresh charge when they step out to remove the nozzle. Hand touches nozzle and the vapor cloud goes boom. This also used to be a problem with cell phones with retractable antennas and you still see the warning signs for them from time to time.
It is truly amazing what total nonsense people will believe in order to justify laws (or really anything else which in their view needs justifying). You can literally drive around 48 states and see that this never happens. It's not a thing. The Mythbusters even did an episode on it years ago and they decided it's not a thing; they were simply unable to get fumes to combust using static electricity, let alone cell phones.
I think you might be remembering this Mythbusters episode backwards; they determined that it wasn't cell phones causing ignition and was in fact static electricity.
There was never regular tipping in this case in the US as far as I can recall.
It really went out during the gas crisis in the 70s. Before that, it was the norm to have full-service which also included washing your windshield and offering to check your oil (which needed to be done more frequently early-on). You were also often paying cash although oil company cards were definitely getting more common at that point.
(But as something of an aside, I recall getting turned down for a gas card in the early 80s because I didn't have a credit history but was able to get an AMEX or something along those lines which helped me establish credit.)
> which needed to be done more frequently early-on
Americans seem to love checking and replacing their oil.
They have whole retail chains devoted to it, when everyone I know in Europe gets it replaced once a year at their annual dealer service, with no checking in between.
> They have whole retail chains devoted to it, when everyone I know in Europe gets it replaced once a year at their annual dealer service, with no checking in between.
Those retail chains will actually do the full periodic servicing that a dealer would. We just refer to that service generically as an “oil change”. And we get that service based on mileage rather than annually.
Also, all Europeans go back to the dealership for periodic maintenance? There are no independent shops that do this? Nobody does it themselves? So if you have a BMW you have to take it to the BMW dealer in particular? Sounds like lock-in to me.
Sorta IMO. The nationwide oil change places, in my experience, check a few high margin parts that they like to replace but don't do any sort of comprehensive periodic servicing like you'd have done at either your dealer or an independent mechanic.
Sure, at least that’s what the dealers and mechanics would want you to think ;)
I’m sure in principle there are many forms of periodic maintenance that need to be done for a car. You’re also supposed to drain your hot water tank every 6-12 months. But getting the oil changed (and the air filters and whatnot) seems to be the important bit.
But there’s multiple competing BMW dealers. You can shop around. If you go somewhere other than a dealer where do they get the training, parts, diagnostic codes to work on your car?
Which is pretty consistent with the context of the comment in general. I'm guessing Germany has a relatively high amount of driving relative to Europe on average and that's within the range where the average driver in Germany is probably fine with a once-per-year oil change. Whereas, in the US, they should be getting one more frequently.
Yes, it does seem like they have a sort of "tradition" about it, possibly due to their larger "classic" engines and to different type of oils.
In EU modern engines with modern oil are (of course it depends) more like to need an oil change every 20.000 kms or more, in practice once per year (and this is a good idea anyway, besides mileage).
Yes, boomers who haven't read an owners manual since 1985 often like to change their oil at 3000 miles.
We have the same oils you have. The same bottle of oil on the shelf here often meets the requirements of both API and ACEA.
But still, the average American drives more than 20,000km per year. The average American male age 35-54 drives 30,000km per year. Most people today are not changing their oil on a whim, they are doing it when their vehicle's maintenance reminder tells them it is time to do so.
My hybrid Toyota tells me it's about time to change my oil about every 12000km
Yep, but there is still something different, as I explained in the linked thread, on my last-before-current car, diesel, board computer reminded me of oil change (actually maintenance "A") around 30,000 kms (which meant - with my mileage at the time - a little over one year), and it is not like the engine suffered in any way as I sold it with nearly 300,000 kms (and 12 years) with the engine still going nicely (it had suspensions to be replaced and a few minor unrelated issues and I had an occasion to get another car with far less kms from another member of the family for a very cheap price).
The context of my comment was that cars used to pretty regularly leak oil to some degree so oil could get low on long drives.
As the sibling comment said, oil changes are (mostly) distance based although, arguably, various commercial interests suggest oil changes more frequently than they are needed. But, if you drive 15,000 miles a year (as is common in the US), you probably want to change your oil more than once a year in any case.
> I'm going to guess that you have to tip them as well?
Regular tipping of gas station attendants is not really a part of New Jersey culture. But people tend to give tips before the holidays, and sometimes during especially bad weather.
It's not terribly uncommon for some jurisdictions (sometimes at a municipal level) to not allow self-serve gas stations. Usually presented as a safety measure, but also an economic one (requires more employees).
yes, but I think for motorcycles, they let you fill on your own because most motorcycle tanks require a little more care from the filler (i.e. you don't just stick it in, turn it on, and wait for it to stop, instead, you're carefully holding the nozzle in the correct orientation and watching the level.)
I only started riding about 6 years ago, whereas I've been driving for 22 years (although the bike is now my main form of transport), so the first time I had to fill up a bike, like an idiot I just stuck the nozzle straight into the fuel tank and pulled the lever all the way like I would for my car... with very predictable results.
25-year motorcyclist here. I've never even considered it possible to fill a motorcycle tank while relying on the automatic shutoff. Do people do that? If I were to put the nozzle of a standard fuel pump into the hole of my tank such that it engages the vapor capture thing, the end of the nozzle will reach down almost to the bottom of the tank.
I put the nozzle to where the tip is as near the top as I can get, then I let it tip and pin itself on the inside. My tank isn't just a hole in the top, there's some kind of metal "basket" in there (2020 XSR 700). I generally do then squeeze it by hand, but I let the auto-shutoff engage.
I would feel fairly comfortable using the auto-shutoff. I have had it fail twice in my life. But, because the tip of the nozzle is so near the exterior of the tank, and the tank is becoming a bottleneck there, there is sometimes a little splashing that gets on the paint.
I've often wondered this myself. Also, because on a couple of occasions, I've had a gas pump (or dispenser?) turn off immediately if I inserted it all the way, but it would work fine if I retracted it a little bit (which made me nervous, because will it still turn off automatically in time if I do that?).
So how is it possible that on some pumps, this trigger system immediately disables the main valve, even when the tank is empty? My best guess is that it's not actually contact with gas in the tank that shuts it off, but air pressure. Air pressure stays constant if I don't insert the handle all the way, but if I do, maybe the air pressure can build up a bit?
So despite Cecil's answer, I still have questions.
You know, half of the reason I come to HN is because it seems like every other thread had someone with a random life experiences to share, like the surprising number of people here with experience is the gas-pumping field.
A drawing would have been nice. Also when mentioning the Bernoulli effect, petrol, cars and it is 1981, then I would like to add that this is the same effect your carburetor uses.
I love mechanisms that rely on laws of physics other than electromagnatism. Seems like in 2020 we reach for the almighty transistor before considering alternative physical solutions.
But yes, I agree... all the fancy remote controlled light bulbs you can get today, still doesn't quite compare to the click of a physical switch and an immediate response :)
Lived in the US a few years, but the feel and sound of switches in Denmark is somehow better :D
It's almost a century old design; I've posted patent links in another top-level comment here. In this case there's no real improvement to be made in adding complexity in the form of electronics, especially in an application involving flammable liquids...
For some reason that I can’t figure out, the dispenser shutoff doesn’t work reliably on my 65 or 66 Mustangs, or at least not fast enough to prevent spillage. Maybe the very short fuel filler hose (from the cap to the top of tank is only maybe 12” of high capacity bent tubing).
If I’m not listening for the noise/pitch change to manually stop, it’s going to splash plenty of gas out the back when the tank fills.
All fuel tanks have a vent valve to redirect vapours from the fuel. During a fillup the turbulent flow of the fuel causes quite a build-up of vapours that need to be redirected.
Persistent fuel overfilling causes fuel to flow into the vent valve, and over time, it clogs. Once clogged, the vapour has no outlet and bubbles up through the main opening, causing the overflow you see on your Mustangs. It’s not the pump’s fault, although the problem is exacerbated when the nozzle does not fit fully into the tank. Car manufacturers always tell people to stop filling after the first click, but most people tend to overfill their tanks regardless. I’m guilty of this too.
Source: Prior stint as a gas jockey and station manager
>All fuel tanks have a vent valve to redirect vapours from the fuel. During a fillup the turbulent flow of the fuel causes quite a build-up of vapours that need to be redirected.
vented fuel tanks began in the 60s. Many older cars have absolutely no vent valve to speak of -- the vapor is dumped from the fuel cap, which acts as a vent; meaning the vent isn't present during fill-up on this style of design.
The vent on the mid-60s Mustang is right back up the fill pipe. In car operation, the cap is vented. (It seems like this thread has told me why it’s not working.)
Funny enough the latter is my home state and the former is my current residence. I don't remember about NJ, but in Oregon, motorcyclists can legally pump their own.
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Some interesting things about gas dispensers/pumps:
- What most people call a gas pump is a dispenser. The actual pump is submersed inside the underground gas tank.
- mid grade gas is just premium and regular gas that is gets mixed at the dispenser before the fuel is dispensed.
- Holding the hose up high and pulling the trigger does not allow more fuel to drain from the hose after reaching your prepaid amount
- people drive off with the nozzle still in their car surprisingly often. There is a magnetic breakaway so the hose will disconnect and not pull the dispenser over.
I can probably think of some more of people are interested