Gas Station Pumping Tips
superuser
Joined: May 2003
Posts: 20,828
Likes: 0
From: Glen Allen VA
Racetracks
Joined: Nov 2002
Posts: 15,668
Likes: 0
From: How long is a piece of string?
Re: Gas Station Pumping Tips
1. Only buy or fill up your vehicle in the early morning when the ground temperature is still cold. Remember that all service stations have their storage tanks buried below ground. The colder the ground the more dense the gasoline, when it gets warmer gasoline expands, so buying in the afternoon or in the evening....your gallon is not exactly a gallon. In the petroleum business, the specific gravity and the temperature of the gasoline, diesel and jet fuel, ethanol and other petroleum products plays an important role. A 1-degree rise in temperature is a big deal for this business. But the service stations do not have temperature compensation at the pumps.
Well, that would be true if the tanks weren't buried, but they are. The ground temperature at 4 feet or deeper below the surface only changes temperature with the seasons, and that takes many weeks. The ground temp below 4 feet still stays within a few degrees the entire year round. So no, the temp of the gas isn't going to rise or fall underground overnight.
However, if the portion of the pump that is above ground was heated by sunlight, then you could build a case. Regardless, gas only expands around 1% per 15 degree temp change. The gas prices fluctuate more than that every day, so is it really worth being that anal about?
3. One of the most important tips is to fill up when your gas tank is HALF FULL or HALF EMPTY. The reason for this is, the more gas you have in your tank the less air occupying its empty space. Gasoline evaporates faster than you can imagine. Gasoline storage tanks have an internal floating roof. This roof serves as zero clearance between the gas and the atmosphere, so it minimizes the evaporation. Unlike service stations, here where I work, every truck that we load is temperature compensated so that every gallon is actually the exact amount.
If Americans would keep the right amount of air in their tires, they could save much more money than the amount they would waste in vapor. Vapor recovery systems are only a few % efficient, so you're not getting robbed by the gas station. I would imagine you'd waste more than the volume of gas vapors just by driving in and out of the gas station twice as often to fill up.
I don't know about you guys, but my time is a lot more valuable than wasting it stopping to fill up every half tank.
Oh, and..
2. When you're filling up do not squeeze the trigger of the nozzle to a fast mode. If you look you will see that the trigger has three (3) stages: low, middle, and high. In slow mode you should be pumping on low speed, thereby minimizing the vapors that are created while you are pumping. All hoses at the pump have a vapor return. If you are pumping on the fast rate, some other liquid that goes to your tank becomes vapor. Those vapors are being sucked up and back into the underground storage tank so you're getting less worth for your money.
4. Another reminder, if there is a gasoline truck pumping into the storage tanks when you stop to buy gas, DO NOT fill up--most likely the gasoline is being stirred up as the gas is being delivered, and you might pick up some f the dirt that normally settles on the bottom. Hope this will help you get the most value for your money.
The moral to this story is: Don't believe stupid shit that circulates around the intarweb preying on people's fear and lack of knowledge. I'm sure you have a lot more common sense than to believe crap like this based on what you know about science and physics and the way the world works. I'm not even going to bother with the "where does our gas come from" part, anyone can write whatever they want and pass it around on a stupid email forward and people will believe it and pass it along to all of the other sheep that they know.
Last edited by Fabrik8; Mar 25, 2008 at 06:14 PM.
Thread Starter
Registered User
Joined: Jun 2005
Posts: 994
Likes: 0
From: Norfolk,VA
Re: Gas Station Pumping Tips
sorry that i have not seen it else where before and hey maybe some others have not either . i also stated that i didn't necessarily agree with it . just trying to see what others thought. isn't this what a forum is for? general discussion of things? so "fail" ? ummm yea guess this is turned in the a bashing forum. Regardless I'm not here to argue with anyone; we all have a right to our own opinion.
Thread Starter
Registered User
Joined: Jun 2005
Posts: 994
Likes: 0
From: Norfolk,VA
Previously Odyssey
Joined: Oct 2004
Posts: 3,273
Likes: 0
From: Virginia Beach
Re: Gas Station Pumping Tips
When the pump stops itself when I am "full", I push the pump lever / switch to shut the pump off. I then pull the gas handle one more time to get that last little bit of gas that is in the pressurized line.
It is not much, maybe 8-10 ounces, but heyyyy...
And I could care less about the other shit posted.
It is not much, maybe 8-10 ounces, but heyyyy...
And I could care less about the other shit posted.
Last edited by Odysseus Prime; Mar 25, 2008 at 06:25 PM.
Thread Starter
Registered User
Joined: Jun 2005
Posts: 994
Likes: 0
From: Norfolk,VA
Re: Gas Station Pumping Tips
Oh my god, where to start. What idiot wrote that article, and where did they get their (mis)information from?
Well, that would be true if the tanks weren't buried, but they are. The ground temperature at 4 feet or deeper below the surface only changes temperature with the seasons, and that takes many weeks. The ground temp below 4 feet still stays within a few degrees the entire year round. So no, the temp of the gas isn't going to rise or fall underground overnight.
However, if the portion of the pump that is above ground was heated by sunlight, then you could build a case. Regardless, gas only expands around 1% per 15 degree temp change. The gas prices fluctuate more than that every day, so is it really worth being that anal about?
If Americans would keep the right amount of air in their tires, they could save much more money than the amount they would waste in vapor. Vapor recovery systems are only a few % efficient, so you're not getting robbed by the gas station. I would imagine you'd waste more than the volume of gas vapors just by driving in and out of the gas station twice as often to fill up.
I don't know about you guys, but my time is a lot more valuable than wasting it stopping to fill up every half tank.
Oh, and..
Pumping slower means pumping longer. More time for liquid gas to evaporate, and more time for your closed fuel system to be open to the air. Waste of money to pump slower. I call bullshit on that myth too...
Pumps have particulate filters, and so does your car.
The moral to this story is: Don't believe stupid shit that circulates around the intarweb preying on people's fear and lack of knowledge. I'm sure you have a lot more common sense than to believe crap like this based on what you know about science and physics and the way the world works. I'm not even going to bother with the "where does our gas come from" part, anyone can write whatever they want and pass it around on a stupid email forward and people will believe it and pass it along to all of the other sheep that they know.
Well, that would be true if the tanks weren't buried, but they are. The ground temperature at 4 feet or deeper below the surface only changes temperature with the seasons, and that takes many weeks. The ground temp below 4 feet still stays within a few degrees the entire year round. So no, the temp of the gas isn't going to rise or fall underground overnight.
However, if the portion of the pump that is above ground was heated by sunlight, then you could build a case. Regardless, gas only expands around 1% per 15 degree temp change. The gas prices fluctuate more than that every day, so is it really worth being that anal about?
If Americans would keep the right amount of air in their tires, they could save much more money than the amount they would waste in vapor. Vapor recovery systems are only a few % efficient, so you're not getting robbed by the gas station. I would imagine you'd waste more than the volume of gas vapors just by driving in and out of the gas station twice as often to fill up.
I don't know about you guys, but my time is a lot more valuable than wasting it stopping to fill up every half tank.
Oh, and..
Pumping slower means pumping longer. More time for liquid gas to evaporate, and more time for your closed fuel system to be open to the air. Waste of money to pump slower. I call bullshit on that myth too...
Pumps have particulate filters, and so does your car.
The moral to this story is: Don't believe stupid shit that circulates around the intarweb preying on people's fear and lack of knowledge. I'm sure you have a lot more common sense than to believe crap like this based on what you know about science and physics and the way the world works. I'm not even going to bother with the "where does our gas come from" part, anyone can write whatever they want and pass it around on a stupid email forward and people will believe it and pass it along to all of the other sheep that they know.
makes sense thanx
Registered Member
Joined: Feb 2006
Posts: 2,173
Likes: 0
Re: Gas Station Pumping Tips
Actually there is some basis for the first one. Just like anything else, gasoline expands when hot and contracts when cold. Gasoline pumps are calibrated to an industry standard temperature. If the station's gasoline is stored at a lower temperature than the standard, then the consumer gets more gasoline than they are paying for. If the gasoline is stored at a higher temperature, then the consumer gets less than they are paying for.
Think about it this way...why does the industry insist on using temperature calibrated pumps in Canada but is opposed to their use in the US?
Think about it this way...why does the industry insist on using temperature calibrated pumps in Canada but is opposed to their use in the US?
Registered member
Joined: Nov 2007
Posts: 265
Likes: 0
From: charlottesville
Re: Gas Station Pumping Tips
some people love being butt heads. this guy was only trying to help. i got the same email.basicaly if we all stop buying from the gas stations that purchase towlhead oil we could actualy stop supporting those terrorist bastards. who feels me??????