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carrie757

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Virginia Beach

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Message Posted: Apr 11, 2013 9:13:53 AM

I recently read a story and figured I would pass along the information. It said to help get the best gas mileage, fill up your gas tank when it is halfway empty, and in the early morning as the pipes under the ground are cooler, causing less gas vapors to expand and consequently save you up to a couple of dollars on each fill up. Also, when pumping your gas, use the slowest setting on the pump so less air gets in your tank and this should also help your fuel efficiency. Every little bit helps right. :)
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Houckster
Champion Author Atlanta

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Message Posted: May 3, 2013 10:08:44 PM

MERTIEMAN writes: This is a complete myth as the underground tanks are always at the same temperature no matter the time of day.
______
Nope, not true. The temperature of gas upon delivery can vary greatly and thus its volume will vary. If the gas arrives "hot" from the distributor, and the station is getting several deliveries daily as the big outlets will, the gas may not have a chance to cool. Like it or not, buying in the morning may be an advantage to the consumer.
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73CH13
Rookie Author Phoenix

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Message Posted: May 3, 2013 1:41:20 PM

Fuel pumps have to meter gas at the same rate no matter what. It's government regulation.
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giwan
Champion Author Michigan

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Message Posted: May 1, 2013 10:35:19 AM

Not true. The difference in temp of the underground tanks makes little to no difference. Ait does not fill up you gas tank.
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MertieMan
Champion Author Lexington

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Message Posted: Apr 22, 2013 5:24:42 AM

This is a complete myth as the underground tanks are always at the same temperature no matter the time of day.
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priver
All-Star Author Alberta

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Message Posted: Apr 21, 2013 10:13:07 PM

yes. I heard this and do..
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WEPSMAN
Champion Author South Dakota

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Message Posted: Apr 21, 2013 9:53:31 PM

Mostly myths. All ideas that some "expert" says will help. There is such minimal impact, you will not even notice.
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GrumpyCat
Champion Author Alabama

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Message Posted: Apr 18, 2013 2:03:33 PM

I recently read a story claiming if you spin around 3 times immediately before putting the nozzle in your gas tank that it imparts an atomic spin on the molecules and burns more completely for better MPG.

Dissenters can not agree whether to spin clockwise or counter-clockwise, and whether it matters if one is in the northern hemisphere or southern.

Others say the direction of spin depends upon which side the gas cap is located.
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Houckster
Champion Author Atlanta

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Message Posted: Apr 18, 2013 12:26:05 PM

Some facts:

The standard coefficient of gasoline’s expansion/contraction equals 0.069% per degree Fahrenheit.

Consumer Watchdog

New Hampshire: Explanation of gasoline metering accuracy.

According to a Wikipedia article: In the United States, the National Institute of Standards and Technology (NIST) specifies the accuracy of the measurements in Handbook 44. Table 3.30 specifies the accuracy at 0.3% meaning that a 10-US-gallon (37.9 L; 8.3 imp gal) purchase could vary between 9.97 US gal (37.7 L; 8.3 imp gal) and 10.03 US gal (38.0 L; 8.4 imp gal) as to the actual amounts at the delivery temperature of the gasoline.

The maximum fuel flow at the pump in the US for consumers is 10 gallons a minute.

Fuel Pumps and fuel metering accuracy

The information in this reference may provide a more optimistic picture than is justified. The volume of fuel pumped may vary far more than is stated.

So how valid is the information that CARRIE757 provides? Not much because there's really no way to predict fuel temperature as it is metered by the pump and US pumps are not designed to adjust for the temperature of the fuel.

It is important to remember that a major outlet for fuel can receive several shipments a day so regardless of the time of day the temperature of the fuel will vary according to the temperature of the fuel when the truck was loaded and it will vary also with the temperature of the service station's storage tank (which is normally insulated to reduce temperature change) and how long the fuel is in the tank. In the first two references I provided, the authors state that during the summer, consumers pay a higher rate for fuel than the pump shows because the gas is metered assuming a 60 degree temperature whereas the fuel will often be warmer. Ten gallons of fuel at 85 degrees does not equal ten gallons of fuel at 45 degrees because the volume of gas at 85 degrees is more than it is at 45 degrees. The New Hampshire study shows this.

How much gas do we get versus how much we pay for will indeed be a function of temperature and there is no definite way to determine this temperature according to the time of day.

And what about gas mileage? Gas mileage will not vary according to the time of day you purchase it as I stated above but it will vary according to temperature. If the conditions are right and the temperature of the fuel is below 60 degrees, you will get more miles to a tank of fuel because the tank will hold more fuel than it would on a hot day because a gallon of fuel will occupy less space in the tank. The New Hampshire study allow you to calculate how many gallons your tank will hold given the volume stated by the OEM and then compensated by fuel contraction or expansion accurding to the temperature.

Clear now? I didn't think so.

[Edited by: Houckster at 4/18/2013 12:29:24 PM EST]
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davisadm
Champion Author Los Angeles

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Message Posted: Apr 18, 2013 11:13:34 AM

"Couple of pennies......maybe."

If even that. Remember that the temp underground is very steady.

"save you up to a couple of dollars on each fill up"
No way would it save you that kind of money. That is misinformed people talking.
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gvan
Champion Author Chicago

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Message Posted: Apr 18, 2013 10:43:15 AM

"....causing less gas vapors to expand and consequently save you up to a couple of dollars on each fill up."

Couple of pennies......maybe.
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dvx4002004
Sophomore Author Medford

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Message Posted: Apr 12, 2013 4:52:16 AM

Yes
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IAMCANADIAN73
Champion Author Ontario

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Message Posted: Apr 12, 2013 12:38:33 AM

Yes
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IAMCANADIAN73
Champion Author Ontario

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Message Posted: Apr 12, 2013 12:38:23 AM

Yes
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dontuknowOH
Champion Author Ohio

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Message Posted: Apr 11, 2013 6:16:01 PM

I would believe all the storage tanks are buried but I don't follow the getting air in the vehicles tank by pumping slow or fast, seems if fuel is being pumped in only evaporation fumes are going to come out,. that is why the vent is there to capture vapors which pollute the atmosphere otherwise.

The actual displacement mechanical pumps probably are at a low storage end of the in-ground tanks (bottom).I can relate to fuel temps being higher when a large fuel transport truck is releasing a refuel supply to a station on a hot Summer day, then dropping off his delivery load of higher temps (not an ideal time) to buy gas then.

Early morning vehicle fuel tank temps would prevent less vapors coming out of the cars tank, but under ground storage temps are really much more stable 24-7.
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OceanArcher
Champion Author Mississippi

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Message Posted: Apr 11, 2013 4:00:19 PM

Hmmmm -- that's a bit strange. Thought all stations had their tanks buried these days ...
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dontuknowOH
Champion Author Ohio

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Message Posted: Apr 11, 2013 10:12:40 AM

A bit horizontal, but thoughts are what makes life Greater, but many of todays pumps are above ground, operating in the sunshine at times are suppose to have vapor sucking recapture vents a their nozzles, so if then a driver takes an additional slow pump speed to fill with vehicle being exposed to operational daily temps for a longer vent sucking time period recovering your vehicle tank's fuel vapors who benefits here? Who collects those energy vapors?

A good advantage of early fueling is also preventing a later day congestion at more busy hours and possibly loosing a frustrated customer to another source, due to a possible customer leaving...That happens!

Welcome and it doesn't hurt to relate any info, its interesting......

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