Cold gas saves you money?

[Rapid Runner]

Is there any truth to this...

I know bout the whole.. "if you see a tanker at the pump run!" thing.. bout pumping gas as its cold and pumping it slow???

[G-Oil Guy]

Ok..I work in the oil industry and refined and produced finished diesel.

On the whole, his facts about the temperature effects on liquids with low boiling temperatures is correct.

that being said, the temperature in the ground will not affect the level of vaporization of the gas while pumping. Same thing with the amount of gas inside your fuel tank upon filling. They don't differ that much and are most likely insulated.

Additionally, this stuff he states about pumps is why the fuel pumps are required to be certified every year (differs on state?) by the department of weights and measures. Also, he doesn't state (and I'm not quite sure) if the pumps are positive displacement pumps. If they are positive displacement, they dispense a fixed and an exact amount every time they move.

His claim about when the tanks are being filled probably does have some merit. But I'm betting those tanks have internal baffles or an area (often called a boot) to catch any water or solids that may enter the tank while being filled. Still, it can't hurt to let the tanks settle for about an hour filling to be safe.

[BloodRain]

All fuels are volume corrected to 15c up here.

[Rapid Runner]

Originally Posted by G-Oil Guy

Ok..I work in the oil industry and refined and produced finished diesel.

On the whole, his facts about the temperature effects on liquids with low boiling temperatures is correct.

that being said, the temperature in the ground will not affect the level of vaporization of the gas while pumping. Same thing with the amount of gas inside your fuel tank upon filling. They don't differ that much and are most likely insulated.

Additionally, this stuff he states about pumps is why the fuel pumps are required to be certified every year (differs on state?) by the department of weights and measures. Also, he doesn't state (and I'm not quite sure) if the pumps are positive displacement pumps. If they are positive displacement, they dispense a fixed and an exact amount every time they move.

His claim about when the tanks are being filled probably does have some merit. But I'm betting those tanks have internal baffles or an area (often called a boot) to catch any water or solids that may enter the tank while being filled. Still, it can't hurt to let the tanks settle for about an hour filling to be safe.

Kinda having a hard time comprehending lol.. but I think I get it

It wouldn't surprise me if the industry tried to take a few nickel and dimes from us.. they already do it to us in the summer lol

[G-Oil Guy]

Originally Posted by Rapid Runner

Kinda having a hard time comprehending lol.. but I think I get it

It wouldn't surprise me if the industry tried to take a few nickel and dimes from us.. they already do it to us in the summer lol

Ok, let me see if I can clarify a little:

Claim: Temperature affects level of vaporization of fuel
My response: This is true.

Claim: The temperature fluctuation in the underground storage tanks can affect the amount of fuel you get so you should only get gas in the morning
My response: these tanks are surrounded by concrete most often when they're installed and they're installed at such a depth that I doubt there is much measurable temperature fluctuation in the tank. Thus the impact on fuel vaporization is probably negligible.

Claim: vapor recovery systems are robbing you of fuel and not providing an exact amount of gasoline
My response: Gasoline pumps are required to be certified on a specified interval (that varies state to state) by the Department of Weights and Measures to prevent fraud and would most likely be caught.

Claim: Pumps induce vaporization of fuel by due to the speed at which they pump and they are not temperature compensated to reduce that.
My response: in refineries and terminals to move that large of a volume you use centrifugal pumps which can induce some vaporization which can make the pump "knock" (there is a real term for it and its escaping me at the moment) causing the liquid amount to be off. HOWEVER, with the small volumes that the individual pumps dispese, I think they might use positive displacement pumps which pump a fixed volume that cannot change. But I'm not positive if they are PD pumps.

Hope that helps.


Also, the stations themselves are most often owned by independent owners who pay a licensing fee to use a big companies name. If you get screwed over, it's by them. The guys who pay the big companies on gasoline are the terminals like the guy was claiming he works at. By the time the gasoline gets to your car, the Big Guys have been paid already.

[DarkneSS]

Even if you get a bit more gas on a cold fill up, I doubt it amounts to anything significant. It probably only matters when you buy thousands of gallons at once.

[GSTRYDR]

Originally Posted by G-Oil Guy

Ok, let me see if I can clarify a little:

Claim: Temperature affects level of vaporization of fuel
My response: This is true.

Claim: The temperature fluctuation in the underground storage tanks can affect the amount of fuel you get so you should only get gas in the morning
My response: these tanks are surrounded by concrete most often when they're installed and they're installed at such a depth that I doubt there is much measurable temperature fluctuation in the tank. Thus the impact on fuel vaporization is probably negligible.

Claim: vapor recovery systems are robbing you of fuel and not providing an exact amount of gasoline
My response: Gasoline pumps are required to be certified on a specified interval (that varies state to state) by the Department of Weights and Measures to prevent fraud and would most likely be caught.

Claim: Pumps induce vaporization of fuel by due to the speed at which they pump and they are not temperature compensated to reduce that.
My response: in refineries and terminals to move that large of a volume you use centrifugal pumps which can induce some vaporization which can make the pump "knock" (there is a real term for it and its escaping me at the moment) causing the liquid amount to be off. HOWEVER, with the small volumes that the individual pumps dispese, I think they might use positive displacement pumps which pump a fixed volume that cannot change. But I'm not positive if they are PD pumps.

Hope that helps.


Also, the stations themselves are most often owned by independent owners who pay a licensing fee to use a big companies name. If you get screwed over, it's by them. The guys who pay the big companies on gasoline are the terminals like the guy was claiming he works at. By the time the gasoline gets to your car, the Big Guys have been paid already.

The term is Cavitate. Just helping out.

[G-Oil Guy]

Originally Posted by 07Tundra

The term is Cavitate. Just helping out.

THANK YOU....been driving me crazy for the last little bit.

I kept saying to myself "I know it starts with a C...ca....ce....ah f*ck it"

[G-Oil Guy]

OH I missed one:

Claim: trucks filling tanks cause dirt and debris to get stirred up and sucked into the pumps and deposited into your tank.

My response: True...to an extent. There is no doubt some deposits in the tank that get stirred up. However, I bet these tanks have internal baffles or boots that are used to collect any debris or water that can enter the tank during filling. Additionally, I bet the gas pumps have filters and your car has a fuel filter. It probably wouldn't hurt much and if you insisted on waiting, I bet you could come back in an hour after the filling truck leaving and you'd be fine.

[derklug]

People can check it themselves, get a graduated cylinder, fill to a line (say 500ml) at room temp. Put the cylinder outside in freezing temps and record the difference. I am guessing less than .5%. 50 cents per $100, or the drop that falls off the end of the nozzle when you remove it.

[bw26ss]

it takes the same amount, roughly to fill up every time i fill up, so what are we talking saving a dollar or something, who cares

[bulllett]

G-Oil Guy has got it right. This claim (and many more) has been around for quite a few years. Ignore it.

MB

[ChrisBlair]

Originally Posted by bulllett

G-Oil Guy has got it right. This claim (and many more) has been around for quite a few years. Ignore it.

MB

I could sit here and type up 1000 words too. Does it make me right if I type a lot on the subject?

[05stram]

Your grip should be the fact you are forced to pump alcohol into your tank when you do not want to. If I want a higher octane fuel then I want a better fuel blend with a higher octane not moonshine in my tank.