# Gas Pump Handles **URL:** \ **Category:** Factual Questions\ **Created:** [May 14, 2001, 7:14pm UTC](https://boards.straightdope.com/t/gas-pump-handles/65430 "2001-05-14T19:14:46Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Drum\_God](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drum_god/32/44_2.png) [@Drum\_God](https://boards.straightdope.com/u/Drum_God)\ **Post date:** [May 15, 2001, 7:11pm UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/21 "2001-05-15T19:11:00Z")
If the hose is pulled out of the pump, it breaks off at a pre-determined point. That break-away point has a shut off valve. The only gas spilled is the fuel between the cut-off and the handle. The gas does not continue spewing uncontrolled. I have noticed that the hold-open latches are primarily missing on pumps with vapor-return hoses. These are mandated on all stations in and around Houston. I have also noticed the latches missing on gas stations in Austin. Both Houston and Austin have had air-quality issues, so I imagine that everything they can do to get people to pay attention as they pump is worthwhile. In the summertime in Austin, the city and state actively discourage people from filling their cars during the heat of the day. The mixture of gasoline fumes and sunlight create an ozone-depleting chemical. The problem is so severe that the local transit authority, Capital Metro, offers free bus fare on so-called “Ozone Action Days.” [begin GD] With all this going on around him, how did GW Bush miss the environmental crisis? Watch out or he’ll do to America what he did to Texas. [/GD] ---
**Author:** ![choosybeggar](https://avatars.discourse-cdn.com/v4/letter/c/8c91f0/32.png) [@choosybeggar](https://boards.straightdope.com/u/choosybeggar)\ **Post date:** [May 15, 2001, 8:20pm UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/22 "2001-05-15T20:20:03Z")
> [@](#): > > \*Originally posted by MrDeath \* > \*\ ***choosybeggar** , I almost liked your response, until you got carried away in your analogy. > > > [@](#): > > > > \*Originally posted by choosybeggar \* > > \*\* > > > > > [@](#): > > > > > > \*Originally posted by MrDeath \* > > > Gasoline is concentrated energy, and if you behave cavalierly around it long enough, you _will_ wind up in a burn ward. > > > \*\* > > > > [snip] > > > > > [@](#): > > > > > > heat of combustion of 1 gram (g) of fat is 9.3 kcal > > > > We get 1 gram of gasoline yielding 43X 0.2388=10.3 kcal > > > > Therefore, fat yields almost as much energy per gram as gasoline. > > > > **Warning label** The makers of Ben and Jerry’s ask you to please refrain from smoking or similar cavalier behaviors while using our product or you **will** wind up in a burn ward 😉 \*\* > > From [the Ben & Jerry’s website](http://www.benjerry.com/product/nutritional.html), the highest-calorie product they make is Cookie Dough Pop, at 410 calories per 1/2 cup. The highest-calorie ice cream/yogurt product they make is Peanut Butter Cup ice cream at 380 calories per 1/2 cup. Assuming that ice cream is half the density of water (it’s more than that, but I’m erring on the side of caution), 1/2 a cup would have about 70 g of mass, yielding 5-6 calories per gram of Ben & Jerry’s, or half that of gasoline. > > The other thing is, energy content is only half the story. Ben & Jerry’s doesn’t burn. In the name of thoroughness, I just tried putting a match on a scoop of the stuff. I got a small dribble of liquefied ice cream, a wet match, and a scoop of ice cream I had to throw out. Gasoline, on the other hand, is _made_ to ignite. The octane rating measures just _how_ eager it is to ignite (the higher the rating, the less eager). I’m not going to repeat my match experiment with a scoop of gasoline though. I’ll leave that to you. Call me from the hospital and tell me how it went. \*\* **Senor D,** I hope you reconsider your position on reading this response and realize that you can _fully_ like my response. My point was that simply by knowing the heat of combustion of a substance, one cannot know it’s potential for explosive oxidation. The Ben and Jerry’s thing (as you rightly point out) was an overextended analogy but was _intended_ to be satirical. However, because I’m feeling cantankerous, I’ll quibble with your post. My understanding is that you **can** put out a match in gasoline. You need to introduce it fast enough to avoid igniting the highly flammable vapors layered above the liquid phase. A nice open container with lots of ventilation would be helpful as well. And this experiment is certainly more worthy of a fella with the moniker **Mr Death** than trying to ignite Ben and Jerry’s, **peanut butter cup**. [sub]Disclaimer: do not try this at home [/sub] ---
**Author:** ![choosybeggar](https://avatars.discourse-cdn.com/v4/letter/c/8c91f0/32.png) [@choosybeggar](https://boards.straightdope.com/u/choosybeggar)\ **Post date:** [May 15, 2001, 8:45pm UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/23 "2001-05-15T20:45:59Z")
**Yo Death** One more thing. You posted > [@](#): > > …you will wind up in a burn ward. and > [@](#): > > Call me from the hospital and tell me how it went. What is it with you and your latent wish for folks to require treatment for serious injury?😃 ---
**Author:** ![MrDeath](https://avatars.discourse-cdn.com/v4/letter/m/22d042/32.png) [@MrDeath](https://boards.straightdope.com/u/MrDeath)\ **Post date:** [May 15, 2001, 9:11pm UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/24 "2001-05-15T21:11:55Z")
> [@](#): > > \*Originally posted by choosybeggar \* > \*\ ***Yo Death** > What is it with you and your latent wish for folks to require treatment for serious injury?😃 \*\* Goes with the job description 😛 ---
**Author:** ![tracer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tracer/32/20578_2.png) [@tracer](https://boards.straightdope.com/u/tracer)\ **Post date:** [May 15, 2001, 9:30pm UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/25 "2001-05-15T21:30:13Z")
[Speaking of gas pump handles…](http://boards.straightdope.com/sdmb/showthread.php?threadid=70976) ---
**Author:** ![brad\_d](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@brad\_d](https://boards.straightdope.com/u/brad_d)\ **Post date:** [May 15, 2001, 9:53pm UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/26 "2001-05-15T21:53:35Z")
Seconding Bob - I’ve yet to run into a station here in SoCal that lacked hold-on clips. I generally buy my gas at Chevron, Shell, or Mobil. I’ve also _never_ had one fail to cut off in my 15 years of driving. How often does this happen? Personally, I like 'em. I might change my opinion if confronted with evidence that their use is an unwarranted risk, but my experience goes against that notion. ---
**Author:** ![racinchikki](https://avatars.discourse-cdn.com/v4/letter/r/eada6e/32.png) [@racinchikki](https://boards.straightdope.com/u/racinchikki)\ **Post date:** [May 16, 2001, 1:12am UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/27 "2001-05-16T01:12:53Z")
I live in upstate NY, and I’ve never used a gas pump that had a catch on it. It’s never even occured to me that there would be one – much less to shove my gas cap in there to act as one! I don’t find it too hard to stand out there and pump my own gas, even when it’s cold out (I have mittens in my car plus I wear driving gloves), and I like having the control over the fuel flow. If you put the catch on and then go do something else, how do you go about topping off a few cents to bring the charge up to an even amount? Also, I think I’d be a lot more likely to forget stuff if I didn’t HAVE to be there pumping. ---
**Author:** ![Hail\_Ants](https://avatars.discourse-cdn.com/v4/letter/h/dc4da7/32.png) [@Hail\_Ants](https://boards.straightdope.com/u/Hail_Ants)\ **Post date:** [May 16, 2001, 1:28am UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/28 "2001-05-16T01:28:40Z")
MrDeath: > [@](#): > > Gasoline is not lighter fluid. Try dousing your charcoal briquets in a little gasoline some time and throwing in a match. Throw the match from at least 10 feet away if you don’t want to be incinerated You’ve totally proven my point about people being big babies. **Incinerated?!?** Not unless you pour the gas on yourself by mistake. I’ve started charcoal like this several times. You drop the match, WHOOSH!, it lights. Big f\*\*\*\*\*\* deal. Gasoline is not plutonium. You are not going to get hurt unless: A. You’re a child or B. You’re an idiot Unfortunately, the reason responsible, intelligent adults can’t have clips on gas pumps is because the world has to be child/idiot proof! ---
**Author:** ![hazel-rah](https://avatars.discourse-cdn.com/v4/letter/h/73ab20/32.png) [@hazel-rah](https://boards.straightdope.com/u/hazel-rah)\ **Post date:** [May 16, 2001, 2:09am UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/29 "2001-05-16T02:09:25Z")
I don’t understand the part about the gas spilling out onto the ground. You flip the latch to secure the handle, walk away, and it stops automatically when the tank is full. In fact, a lot of times it stops before the tank is even close to being filled up. I’ve done this probably hundreds of times and never even come close to spilling gas from overflow. I drove a van once where for some reason it was near impossible to make the pump even _start_ pumping gas, never mind overflowing the tank. What gives? I use the latch because I hate the smell of gasoline, so I start it up and walk away from the car. I hate cars. -fh ---
**Author:** ![wooba](https://avatars.discourse-cdn.com/v4/letter/w/aeb1de/32.png) [@wooba](https://boards.straightdope.com/u/wooba)\ **Post date:** [May 16, 2001, 3:45am UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/30 "2001-05-16T03:45:52Z")
> [@](#): > > **If you put the catch on and then go do something else, how do you go about topping off a few cents to bring the charge up to an even amount?** It still operates as normal. You can press it again to top off the tank… ---
**Author:** ![Seven](https://avatars.discourse-cdn.com/v4/letter/s/3d9bf3/32.png) [@Seven](https://boards.straightdope.com/u/Seven)\ **Post date:** [May 16, 2001, 8:28am UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/31 "2001-05-16T08:28:45Z")
Don’t ask me. I live in Oregon USA. The general public isn’t allowed to pump their own gas. We’re too stupid or just spoiled. I’ve yet to figure it out. ---
**Author:** ![DougC](https://avatars.discourse-cdn.com/v4/letter/d/7feea3/32.png) [@DougC](https://boards.straightdope.com/u/DougC)\ **Post date:** [May 16, 2001, 9:42am UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/32 "2001-05-16T09:42:58Z")
> [@](#): > > Don’t ask me. I live in Oregon USA. The general public isn’t allowed to pump their own gas. We’re too stupid or just spoiled. I’ve yet to figure it out. - Seven - - - Um, I don’t know which _you_ are, but on average, Oregonians would seem to be stupid. Oregon has laws that say that you must pay for a professional idiot to pump your gas, and so whenever you buy gas you are paying for the gas plus the idiot’s paycheck. Pumping gas isn’t real difficult, it doesn’t take a master’s degree in Gasology. - RedDawgEsq: Where I am, the gas nozzles are made out of aluminum. - choosybeggar: it’s _lit cigarettes_, not lit matches: gasoline can be lit with a spark or a flame, but not a smoldering fire. - MrDeath: gasoline is not explosive. ---
**Author:** ![pldennison](https://avatars.discourse-cdn.com/v4/letter/p/9fc29f/32.png) [@pldennison](https://boards.straightdope.com/u/pldennison)\ **Post date:** [May 16, 2001, 12:45pm UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/33 "2001-05-16T12:45:39Z")
A recent item in Bob Levey’s column in the _Washington Post_ referred to some area stations removing the clips from the handles for a slightly different safety reason. Some customers had gotten in the habit of engaging the clips, letting the auto shut-off do its thing, then replacing the handle without disengaging the clip. The next customer would grab the handle, turn on the pump and, with the clip still engaged, find the ground, the car or their clothes doused with gasoline. ---
**Author:** ![smoke](https://avatars.discourse-cdn.com/v4/letter/s/c5a1d2/32.png) [@smoke](https://boards.straightdope.com/u/smoke)\ **Post date:** [May 16, 2001, 1:07pm UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/34 "2001-05-16T13:07:35Z")
> [@](#): > > \*Originally posted by pldennison \* > \*\*A recent item in Bob Levey’s column in the _Washington Post_ referred to some area stations removing the clips from the handles for a slightly different safety reason. Some customers had gotten in the habit of engaging the clips, letting the auto shut-off do its thing, then replacing the handle without disengaging the clip. The next customer would grab the handle, turn on the pump and, with the clip still engaged, find the ground, the car or their clothes doused with gasoline. \*\* :eek: Well, that pretty much seals it for me. I hadn’t even considered that possibility, but damn would I be PISSED it that happened to me! Nice way to start your day.😃 So, for me, the question that remains, (and will probably go unanswered unless we have a new-station owner on the boards here) is: Why don’t they just start buying handles without the clips in the first place, and why has this all come to a head now? (If a subject as innane as this could actually come to a head, that is) ---
**Author:** ![sdimbert](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sdimbert/32/20204_2.png) [@sdimbert](https://boards.straightdope.com/u/sdimbert)\ **Post date:** [May 16, 2001, 4:30pm UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/35 "2001-05-16T16:30:46Z")
> [@](#): > > \*Originally posted (waaaay back up there) by Hail Ants \* > \*\*…it **is** illegal to jam your gas cap into the handle to hold it on. I always do it anyway, while dialing my cell phone! People are such babies about gasoline. \*\* Ummm… isn’t cell phone use prohibited (or at least frowned upon) by gas pumps for some reason? Didn’t I read a thread here in GQ about this some months ago? Something to do with EM energy? Am I making this up? ---
**Author:** ![breaknrun](https://avatars.discourse-cdn.com/v4/letter/b/bbce88/32.png) [@breaknrun](https://boards.straightdope.com/u/breaknrun)\ **Post date:** [May 16, 2001, 5:58pm UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/36 "2001-05-16T17:58:02Z")
> [@](#): > > \*Originally posted by pldennison \* > \*\*A recent item in Bob Levey’s column in the _Washington Post_ referred to some area stations removing the clips from the handles for a slightly different safety reason. Some customers had gotten in the habit of engaging the clips, letting the auto shut-off do its thing, then replacing the handle without disengaging the clip. The next customer would grab the handle, turn on the pump and, with the clip still engaged, find the ground, the car or their clothes doused with gasoline. \*\* Umm, I don’t see how this can be. With the latch engaged, if the hose shuts off, you have to disengage the latch and then squeeze the handle again to get more gas to pump. **sdimbert** I’m not sure about the cell phone thing but lots of gas stations now are posting warnings to stay out of your car while pumping gas because people tend to pick up static electricity which can ignite the gas fumes. I just did a quick google search and found this hit: [http://www.osmre.gov/safety/stip0101.htm](http://www.osmre.gov/safety/stip0101.htm) > [@](#): > > Even though people are the main problem, one contributor to the problem is the hold-open clip on gas nozzles. Some local jurisdictions don’t allow hold-open clips on gas nozzles because of the potential for static electricity sparks. > > Safety Tip: Static electricity can ignite gasoline vapors. Stay near your vehicle and do not re-enter it while fueling. If you do re-enter your vehicle during fueling, touch a metal part of your vehicle BEFORE touching the gasoline nozzle to discharge any potential static buildup. ---
**Author:** ![Odieman](https://avatars.discourse-cdn.com/v4/letter/o/a87d85/32.png) [@Odieman](https://boards.straightdope.com/u/Odieman)\ **Post date:** [May 16, 2001, 6:39pm UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/37 "2001-05-16T18:39:52Z")
I’ve told this story here a looong time ago. The last time I used one of those clips was the time I was pumping gas at a self-serve station. It was about -20C and I had on heavy leather mitts, so I couldn’t really grip the pump, so I was using the nozzle. My car has the filler to the gas tanks at a funny angle and the pump has to be manually held in place. I was holding the hose when it slipped and the gas started pouring out of the pump…I ended up with my pants, down coat and gloves thouroughly saturated, probably three litres spilled out before I could grab the nozzle and stop it. I had to wash the clothes four times before I could get the smell out, the gloves were a write-off though. I was just praying that someone wouldn’t smoke because I knew I would become Odie flambe…so I guess one of the reason they are taking the locks off of gas pumps is because of idiots like me. Keith ---
**Author:** ![MrDeath](https://avatars.discourse-cdn.com/v4/letter/m/22d042/32.png) [@MrDeath](https://boards.straightdope.com/u/MrDeath)\ **Post date:** [May 16, 2001, 7:10pm UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/38 "2001-05-16T19:10:25Z")
[QUOTE] \*Originally posted by MC \* \*\* > [@](#): > > - MrDeath: gasoline is not explosive. \*\* [Gasoline](http://www.shell.ca/code/motoring/tips/gasoline.html) [_is_](http://www.mcmua.com/hazardouswaste/FAQ_Gasoline.htm) [explosive.](http://www.canadiandriver.com/articles/jk/at_000814.htm) From the first cite: > [@](#): > > the vapors from just one cup of gasoline have the explosive force of five sticks of dynamite. From the second: > [@](#): > > Gasoline is highly flammable and can be explosive. From the third: > [@](#): > > Gasoline has more explosive power than dynamite but we sometimes take it for granted because it is available everywhere. I know of two commercial repair shops that burned to the ground because gasoline came into contact with an ordinary trouble light! ---
**Author:** ![Irishman](https://avatars.discourse-cdn.com/v4/letter/i/b487fb/32.png) [@Irishman](https://boards.straightdope.com/u/Irishman)\ **Post date:** [May 16, 2001, 8:15pm UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/39 "2001-05-16T20:15:25Z")
Thanks for posting this, Smoke. When I was younger, they were all over the place. Now I can hardly find a place that still has the clips intact. This includes Texas, Arkansas, and Oklahoma. (Don’t ask why. ;)) Here’s my reason for liking the clips - my tank inlet is just below the comfortable position to hold the nozzle. I have to bend over to hold the pump in place so I can hold the handle. This gets uncomfortable. I would love to be able to set the clip, and then actually stand upright, or sit down in my seat, or wash the windows. But I have to stoop over, or squat, or otherwise attain an uncomfortable position and hold the handle, which often gets tiring to hold - some of those pumps are kinda slow. This was worse on my old car. I drove an '82 Buick Regal with the tank inlet behind the license plate. I’d have to fold down the turbo-spring loaded license plate, remove the cap, and insert the pump handle. Then try stooping the whole time. NOT FUN! 1. The only reason I can think is if the auto shutoff failed, you’re not necessarily standing next to the handle to shut it off manually. _shrug_ Someone also mentioned forgetting to remove the handle. I’d laugh, but a certain poster (beatle) actually did this. Drove off down the road with the handle in the inlet, hose trailing behind. 2. Yes, it is more widespread than MA. 3. Shake real good. _ba dum bump_ You have to hold it and let it drain, don’t you? Cabbage, I’ve never heard of the nozzle falling out before. You must have a strage car. I’m trying to figure out how a nozzle could fall out. MC said: > [@](#): > > When a nozzle is brand-new the auto-shutoff mechanism works perfect, but as the nozzle gets old it automatically shuts off less and less, until the auto-shut-off doesn’t work at all. I’ve never experienced that, but I guess it happens. I guess removing the clips forces you to stand there, whereas if you have the clip you could walk off. MrDeath said: > [@](#): > > Gasoline is not lighter fluid. Try dousing your charcoal briquets in a little gasoline some time and throwing in a match. Throw the match from at least 10 feet away if you don’t want to be incinerated. Gasoline is concentrated energy, and if you behave cavalierly around it long enough, you will wind up in a burn ward. The father of a coworker of mine was working on his van, messing with his carburator. He was pouring gasoline in from the top for some reason. It blew up, he was massively burned. He died not long after. Yes, gasoline is dangerous. But there are full-service stations? I thought they were extinct? gadgetgirl said: > [@](#): > > They are trying to prevent drive aways. > The little clips make it easier for people to just get in the car while the pump is still going and take off. What do you think the gas station operator is going to worry about, the driver that just made off with $20 worth of gas or the combustable liquid spewing all over the pavement? Sorry, I don’t buy that. While I concede there might be people vile enough to do that, it would be difficult. Usually the handles don’t pop out of the car, but rather the hoses break at the saftey valve. So they would be driving down the road with a tail. Not very inconspicuous. And it makes them not only theives, but vandals as well. As for stopping drive-aways, I think the pay before you pump is a better deterent than removing the clips. If the gas won’t pump, you can’t steal the gas. (Not that I like pay before you pump, because I don’t know how much gas I’m going to get. I want to fill the tank, not put in a set amount.) Hail Ants said: > [@](#): > > You’ve totally proven my point about people being big babies. **Incinerated?!?** Not unless you pour the gas on yourself by mistake. I’ve started charcoal like this several times. You drop the match, WHOOSH!, it lights. Big f\*\*\*\*\*\* deal. Gasoline is not plutonium. The problem with gasoline is not just the liquid, but the vapor. Gasoline vapor is much more volitile, and it spreads more quickly. Putting some gas on the charcoal and lighting immediately may work okay, but let the gas sit for a few minutes (while hunting up the matches), especially if it isn’t very ventilated (like a calm day, no wind), then try to light the match and you can get burned. pldennison said: > [@](#): > > A recent item in Bob Levey’s column in the Washington Post referred to some area stations removing the clips from the handles for a slightly different safety reason. Some customers had gotten in the habit of engaging the clips, letting the auto shut-off do its thing, then replacing the handle without disengaging the clip. The next customer would grab the handle, turn on the pump and, with the clip still engaged, find the ground, the car or their clothes doused with gasoline. That seems odd. All the handles I’ve seen with clips would automatically release the clip with the auto-shut off. They’re spring loaded, and the auto shut off triggers the handle to pop. It releases from the catch, and the catch moves out of the way. In fact, I’ve even seen pumps that you cannot place the handle back on the pump with the catch engaged. It seems to me these solutions would allow the use of catches while precluding the problem you allude to. Balthisar said: > [@](#): > > One thing that I hope _is not_ becoming a trend: recently while “paying at the pump” the darned-tooting (trying not to swear now) pump charged my credit card and printed my receipt as soon as the pump automatically turned off. It didn’t give me a chance to top off! Well, there is a reason - they don’t want you to top off. Have you read any of the new stickers they’re now putting all over gas pumps? There’s a lot of new hoopla over gasoline fumes contributing to smog. Thus some places now require the pumps to have vapor return hoses, and they don’t like topping off because some of that extra gas is still in the nozzle when you remove it, and it drips out onto the ground and evaporates. This is alleviated by not topping off, because of how the shut off works. The shut off trigger is in the tip of the nozzle. See those little holes around the end? Those are related. As the shut off triggers, the gas is just at the tip of the nozzle. If you continue to pump gas, it goes up around the nozzle in the tube. Usually you retract the nozzle a bit to keep from retriggering the shut off. See [http://www.pa.msu.edu/~sciencet/ask\_st/122591.html](http://www.pa.msu.edu/~sciencet/ask_st/122591.html) . ---
**Author:** ![Balthisar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/balthisar/32/2825_2.png) [@Balthisar](https://boards.straightdope.com/u/Balthisar)\ **Post date:** [May 16, 2001, 10:21pm UTC](https://boards.straightdope.com/t/gas-pump-handles/65430/40 "2001-05-16T22:21:08Z")
> [@](#): > > \*Originally posted by Irishman \* > \*\*Balthisar said: > > > [@](#): > > > > One thing that I hope _is not_ becoming a trend: recently while “paying at the pump” the darned-tooting (trying not to swear now) pump charged my credit card and printed my receipt as soon as the pump automatically turned off. It didn’t give me a chance to top off! > > Well, there is a reason - they don’t want you to top off. Have you read any of the new stickers they’re now putting all over gas pumps? There’s a lot of new hoopla over gasoline fumes contributing to smog. Thus some places now require the pumps to have vapor return hoses, and they don’t like topping off because some of that extra gas is still in the nozzle when you remove it, and it drips out onto the ground and evaporates. This is alleviated by not topping off, because of how the shut off works. The shut off trigger is in the tip of the nozzle. See those little holes around the end? Those are related. As the shut off triggers, the gas is just at the tip of the nozzle. If you continue to pump gas, it goes up around the nozzle in the tube. Usually you retract the nozzle a bit to keep from retriggering the shut off. See [http://www.pa.msu.edu/~sciencet/ask\_st/122591.html](http://www.pa.msu.edu/~sciencet/ask_st/122591.html) . > \*\* That could be a valid reason in other states – I know Nevada has those vapor-recovery do-dads. The first time I tried to pump gas there, I had to go in and ask for help – the pump wouldn’t turn on. Apparently you have to really, forcefully stick it in there, kind of like a grudge-love-making-session :). However, we don’t have those vapor-recovery devices here. And I’m glad – I don’t want the vapor _I’m_ paying for to be recycled by the gas station without a rebate. Better to liberate it. If I really want to top off at that station (which I won’t go to now), I’d just not pay-at-the-pump. Then they couldn’t really stop me. [Previous page](https://boards.straightdope.com/t/gas-pump-handles/65430.md?page=1) [Next page](https://boards.straightdope.com/t/gas-pump-handles/65430.md?page=3)