Truth or wives tale?

[Rayvyn]

I got this in a message today and thought I'd pass it along.

Fact or fiction?


1. Fill up your car or truck in the morning when the temperature is
still cool. Remember that all service stations have their storage tanks buried below ground; and the colder the ground, the denser the gasoline. When it gets warmer gasoline expands, so if you're filling up in the afternoon or in the evening, what should be a gallon is not exactly a gallon.
In the petroleum business, the specific gravity and temperature of the fuel (gasoline, diesel, jet fuel, ethanol and other petroleum products) are
significant. Every truckload that is loaded is temperature-compensated so
that the indicated gallonage is actually the amount pumped. A one-degree
rise in temperature is a big deal for businesses, but service stations
don't have temperature compensation at their pumps .

2. If a tanker truck is filling the station's tank at the time you want
to buy gas, do not fill up; most likely dirt and sludge in the tank is
being stirred up when gas is being delivered, and you might be transferring that dirt from the bottom of their tank into your car's tank .

3. Fill up when your gas tank is half-full (or half-empty), because the
more gas you have in your tank the less air there is and gasoline
evaporates rapidly, especially when it's warm. (Gasoline storage tanks
have an internal floating 'roof' membrane to act as a barrier between the gas and the atmosphere, thereby minimizing evaporation . )

4. If you look at the trigger you'll see that it has three delivery
settings: slow, medium and high. When you're filling up do not squeeze
the trigger of the nozzle to the high setting. You should be pumping at the
slow setting, thereby minimizing vapors created while you are pumping.
Hoses at the pump are corrugated; the corrugations act as a return path
for vapor recovery - from gas that already has been metered. If you are
pumping at the high setting, the agitated gasoline contains more vapor, which is being sucked back into the underground tank - so you're getting less gas for your money .

[Learpilot]

I got this in a message today and thought I'd pass it along.  

Fact or fiction?


1. Fill up your car or truck in the morning when the temperature is
still cool. Remember that all service stations have their storage tanks buried below ground; and the colder the ground, the denser the gasoline. When it gets warmer gasoline expands, so if you're filling up in the afternoon or in the evening, what should be a gallon is not exactly a gallon.  
In the petroleum business, the specific gravity and temperature of the fuel (gasoline, diesel, jet fuel, ethanol and other petroleum products) are
significant. Every truckload that is loaded is temperature-compensated so
that the indicated gallonage is actually the amount pumped. A one-degree
rise in temperature is a big deal for businesses, but service stations
don't have temperature compensation at their pumps .

2. If a tanker truck is filling the station's tank at the time you want
to buy gas, do not fill up; most likely dirt and sludge in the tank is
being stirred up when gas is being delivered, and you might be transferring that dirt from the bottom of their tank into your car's tank .

3. Fill up when your gas tank is half-full (or half-empty), because the
more gas you have in your tank the less air there is and gasoline
evaporates rapidly, especially when it's warm. (Gasoline storage tanks
have an internal floating 'roof' membrane to act as a barrier between the gas and the atmosphere, thereby minimizing evaporation . )

4. If you look at the trigger you'll see that it has three delivery
settings: slow, medium and high. When you're filling up do not squeeze
the trigger of the nozzle to the high setting. You should be pumping at the
slow setting, thereby minimizing vapors created while you are pumping.
Hoses at the pump are corrugated; the corrugations act as a return path
for vapor recovery - from gas that already has been metered. If you are
pumping at the high setting, the agitated gasoline contains more vapor, which is being sucked back into the underground tank - so you're getting less gas for your money .

I know when we fill our Learjet in the winter we can get about 300 to 400 more pounds of jet fuel in our tank. Most of the time we get fuel from a truck and not in the ground. The ground temp is about 55 degrees where the truck temp is a little cooler that outside air temp.
I know when I first was flying jets I was a copilot in Minneapolis in the winter (about minus 20 degrees). I was told by the Captian to go and get the Jet (Sabreliner 40) toped off. I know it holds only 7000 lbs of fuel. When I looked at the fuel gauge it said 7300 lbs. I knew I was in deeeeep trouble for over filling the tanks, but everything worked out A-OK.
Rick Harris

[t-vicky]

Don't know about the rest of them but, #1  I can tell you about.  Years ago I topped off my 57 F-100 with gas early in the morning, (about 30 degrees temp) then pulled it inside for a lube job. Got it up on the lift (65 degrees) & about 5 minutes later the gas starts dripping out the filler spout.  I should have let it down & rolled it outside but no, the gas line hooks right here at the back of the cab, I will just drain a little out.  About 4 gallons later it finally quit leaking out the filler.

[tomslik]

I got this in a message today and thought I'd pass it along.

Fact or fiction?


1. Fill up your car or truck in the morning when the temperature is
still cool. Remember that all service stations have their storage tanks buried below ground; and the colder the ground, the denser the gasoline. When it gets warmer gasoline expands, so if you're filling up in the afternoon or in the evening, what should be a gallon is not exactly a gallon.
In the petroleum business, the specific gravity and temperature of the fuel (gasoline, diesel, jet fuel, ethanol and other petroleum products) are
significant. Every truckload that is loaded is temperature-compensated so
that the indicated gallonage is actually the amount pumped. A one-degree
rise in temperature is a big deal for businesses, but service stations
don't have temperature compensation at their pumps .


probably one of the reasons the tanks are in the ground.
it's a more stable temp down there


2. If a tanker truck is filling the station's tank at the time you want
to buy gas, do not fill up; most likely dirt and sludge in the tank is
being stirred up when gas is being delivered, and you might be transferring that dirt from the bottom of their tank into your car's tank .


sounds logical to me so i don't

3. Fill up when your gas tank is half-full (or half-empty), because the
more gas you have in your tank the less air there is and gasoline
evaporates rapidly, especially when it's warm. (Gasoline storage tanks
have an internal floating 'roof' membrane to act as a barrier between the gas and the atmosphere, thereby minimizing evaporation . )

and spend 20 min at the pump twice as many times to save .05....




4. If you look at the trigger you'll see that it has three delivery
settings: slow, medium and high. When you're filling up do not squeeze
the trigger of the nozzle to the high setting. You should be pumping at the
slow setting, thereby minimizing vapors created while you are pumping.
Hoses at the pump are corrugated; the corrugations act as a return path
for vapor recovery - from gas that already has been metered. If you are
pumping at the high setting, the agitated gasoline contains more vapor, which is being sucked back into the underground tank - so you're getting less gas for your money .

see #3 answer

[wayne petty]

I got this in a message today and thought I'd pass it along.

Fact or fiction?


1. Fill up your car or truck in the morning when the temperature is
still cool. Remember that all service stations have their storage tanks buried below ground; and the colder the ground, the denser the gasoline. When it gets warmer gasoline expands, so if you're filling up in the afternoon or in the evening, what should be a gallon is not exactly a gallon.
In the petroleum business, the specific gravity and temperature of the fuel (gasoline, diesel, jet fuel, ethanol and other petroleum products) are
significant. Every truckload that is loaded is temperature-compensated so
that the indicated gallonage is actually the amount pumped. A one-degree
rise in temperature is a big deal for businesses, but service stations
don't have temperature compensation at their pumps .

the gas station turbine pumps are cooled by the gasoline in the main tank
, if the dealer plays it close to the low limit it tends to heat the fuel and burn out the pumps also.


2. If a tanker truck is filling the station's tank at the time you want
to buy gas, do not fill up; most likely dirt and sludge in the tank is
being stirred up when gas is being delivered, and you might be transferring that dirt from the bottom of their tank into your car's tank .

yes it does stir it up and there may be water stired up also.

3. Fill up when your gas tank is half-full (or half-empty), because the
more gas you have in your tank the less air there is and gasoline
evaporates rapidly, especially when it's warm. (Gasoline storage tanks
have an internal floating 'roof' membrane to act as a barrier between the gas and the atmosphere, thereby minimizing evaporation . )

filling your tank at half may inprove the life of your intank fuel pump.
your fuel pump ceramic bushings are fuel lubed and running it below 1/4 allow air to be sucked up through the pump and allows the pump to run dry.. pumps spin at over 5,000 rpms.. when they get noisy it may be time for a change..  many professional techs now have low amp probes along with digital storage scopes and can clamp their clamp over the fuel pump wire and see how the brushes communator are..

biggest problem is the lack of people chagning fuel filters.. most systems are a return type and continuisly recirculate the fuel through the filter. when the filter gets dirty the pump works harder and hardewr until it the filter does not flow any more..

4. If you look at the trigger you'll see that it has three delivery
settings: slow, medium and high. When you're filling up do not squeeze
the trigger of the nozzle to the high setting. You should be pumping at the
slow setting, thereby minimizing vapors created while you are pumping.
Hoses at the pump are corrugated; the corrugations act as a return path
for vapor recovery - from gas that already has been metered. If you are
pumping at the high setting, the agitated gasoline contains more vapor, which is being sucked back into the underground tank - so you're getting less gas for your money .

the delivery hose is smooth inside.. the outer hose if for return vapors.. out here in california there are limiters on fuel flow at the hose conection.  on trips i have been at stations that pumpped so fast the fill was over before i could get the window done..

i just rembembered when someone drove off with a nozzle and the attendant was trying to fold the end of the hose over to stop the flow...NOT!!! i had to run all the way from the shop to flip off the handle..

i was even there on day when on attendant tryed to collect for 18 gallons of gas from a 65 volkswagen bug owner... it was a real screaming match.. and the dub still on showed 1/8 of a tank...
the pin on the turn on lever was worn. so the pump did not reset from the motorhome just before...the attendant on the outside lane came back from break and settled it.. it was the last full service shell station in los angeles.. 4 lanes four attendants. windows, oil checks, tire checks...

[Crosley.In.AZ]

I do know the specific gravity is important.. temp too on the pumping of the fuel.  My brother operated a pumping staion in El    Paso TX for 33 yrs , then retired.

I may remember to ask him.

Since this is on the internet , I imagine it is correct.


:oops:

[TJ's Dad]

Since this is on the internet , I imagine it is correct.

Yep ... like newspapers .....

The only thing in em i believe is the price n date ... and sometimes the price rises without us noticing ... other times i forget what day it is !!        

[Dave]

Look back many years ago when the race teame started cooling the tanks the fuel was in.. Why because they could get more in the car on the pit stop..
Yup it really works..
Dave

[unklian]

#1 I think the newer style digital gas pumps are temperature compensated.

#2 Makes sense.

#3 Doesn't make sense,in a modern vehicle with all the pollution controls.Gasoline vapors are contained within the system.That's why
gas caps are not vented.

#4 Self serve nozzles don't have "settings".The flow rates are limited
by the pump to reduce the amount of vapor lost.Up here they lowered
the flow rates to reduce pollution.Now the pumps run slow for the first $20,
then they speed up.The difference is signifigant if you are looking for it.

The gas pump can't suck vapor back into the underground tank.
It creates pressure,not vacuum;there is only one hose,so it can't
do both at the same time.
--------
Ever notice how most gas stations have tall stainless flag poles ?
Take a look at the top of the flag pole the next time a tanker is delivering gas at a station.The flag poles are also vent stacks for the underground tanks.If the light is right,you will see the vapor streaming out of the vent as the tank is filled.So much for emission control systems.

[purplepickup]

#3 Doesn't make sense,in a modern vehicle with all the pollution controls.Gasoline vapors are contained within the system.That's why
gas caps are not vented.

I had the air pollution warning light on my dash come on the other day right after I filled up.  I wonder if it is because I kept filling beyond the click off.  If the fuel expands and gets into the contained vapor system will it make that happen?

[Harry]

#1... The storage tanks are more than 6' below ground. The temperature there does not change with the surface temperature.

[river1]

want to do something about it

http://www.consumerwatchdog.org/energy/hotfuelripoff/

later jim

[jaybee]

I don't know if they're true but they can't be wive's tales...

My wife never heard of this stuff.

[wayne petty]

Ever notice how most gas stations have tall stainless flag poles ?
Take a look at the top of the flag pole the next time a tanker is delivering gas at a station.The flag poles are also vent stacks for the underground tanks.If the light is right,you will see the vapor streaming out of the vent as the tank is filled.So much for emission control systems.

one day i bought some gas and noticed someting happening over by the vent stacks... somenut case had crashed his car and was using the vent stacks as a pulling post to wrap some chain around and back his car away from..i ask him..just what do you think those pipes are attached too??? when i told him. the blood ran out of his face.,..

[Carps]

The oil companies know all this and worked out years ago how to use it to screw you.

You cannot beat them at their own game.