Are you concerned about the few pennies ( penny ) that you would save, or the accuracy of the amount of gas that is displayed ?
I try to pump slowly because of the way that the nozzle will shut off before the tank is trully full. When you pump fast, the fuel sloshes around, and from what I have read, this can cause the pump to shut down when it gets hit by the fuel that is splashed upwards on an unfull tank.
According to a petrolium expert if you pump slowly the gas liquid entering your tank does not evaporate as much and get sucked back into the pump nozzle taking back what you just pumped. Apparently "he" thinks that it can be a significant amount of fuel - he also recommends filling up after a cold night so you get colder gasoline from the underground tanks which is more dense thus getting more molecules per gallon volume. As far as getting the tank full the only full tank is one that you can see the gasoline in the filler hole. Any other method is relying on the flow rate of the fuel going down the filler neck and the ability of the air to vent form the tank as you are filling it.
...he also recommends filling up after a cold night so you get colder gasoline from the underground tanks which is more dense thus getting more molecules per gallon volume...
So.... if permafrost in the midwest goes down like 2 feet over the season, hows the gas in the tank 10 feet below ground gonna change temps noticeably overnight?
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1990 Toyota Cressida 7M-GE 3.0 I6/5-speed manual
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Well first the take TOP is not 10 feet under the ground and the frost line is where the ground FREEZES. It still gets cold deeper down since the top of the tank is not that far below ground. I also think that the delivery truck is getting cooled off if it travels in cold weather getting from the terminal to the station. I guess we REALLY NEED TO MEASURE THE GAS TEMPERATURE when we fill up our tanks!
I had some really warm gas come out of a pump in PA once and if you feel the hose as you pump the fuel as I sometimes do it is pretty cold. Tell you all what . . . I am on empty now so when I go for gas in the next day or so I will bring my IR Temp probe with me and measure the fuel line on the pump as I fill it and check the ground temp around the tanks too and see what kind of numbers I get. Next we will need fuel temp reading in the gas log?
i believe pumping slowly does help by retaining more gas in the tank. Brucepick theorized that it keeps the gas from sloshing around in the tank possibly allowing for a more complete fill(at least more accurate to the pump).
it's a pretty cheap test, costing only a bit extra time to fill. during my first slow fill, my FE(calculations) dropped as perhaps more fuel was retained to divide by miles. afterwards, my #s returned to an "above" normal.
so, in theory, if i tried a normal(quick) fill, the #s should be above normal. i say normal(and i can) because i drive the same miles, use the same gas and pump, dive the same speed, etc EVERY week. the only exception is when noted, be it vacation miles or what not. maybe someone else could try this as i do not want to take a hit on FE.
- he also recommends filling up after a cold night so you get colder gasoline from the underground tanks which is more dense thus getting more molecules per gallon volume. As far as getting the tank full the only full tank is one that you can see the gasoline in the filler hole. Any other method is relying on the flow rate of the fuel going down the filler neck and the ability of the air to vent form the tank as you are filling it.
I read some where that Canada actually has meters in the gas station to adjust for the temperature since on average it is colder there than it is warmer. If they didn't adjust for it then the consumer would benefit over time. In the U.S. though since we have more warm days than cold on average they don't adjust for it. The gas stations are winning here. I wish I could find that article. Hope it makes sense.