10 ways to save gas- acoording to GM

[Ray McIntireJr]

On their website GM posts 10 ways to save gas. Most of them are common sense things like no rooftop carriers, don't accelerate uphills, no hard stops or starts etc. One has me a little puzzled tho, it says to stop pumping gas when the nozzle automatically shuts off. Why or how do you suppose this will save someone gas?

 

[Joe Rampino]

I think they're saying not to fill the tank's filler neck with gas. Two things could happen; You could spill a few drops when it reaches the top, or the fuel in the filler neck will expand and dissipate before it has a chance to get into the tank.

 

[Nelson Atwell]

No link?

 

[Matthew Pickwell]

I have been told that if you pump gas to the top of the tank, it chokes flow a bit since there is no air to help the flow (bad on fuel pump as well). It would be like pouring gas out of your gas can to your mower, without opening the vent; the can caves in trying to get air to help flow. Hope that makes sense.

 

[The Boss 2]

i've heard the same thing before, and i always immediately stop when the pump shuts off on the auto thing. i think it has something to do with the filter, but that person may have been wrong when they told me...

 

[Richard L]

It is not good to fill the tank to the top of the filler neck, but I do that occasionally to get an accurate gas mileage calculation.



It's the only way to accurately test MPG. If you don't fill it to the brim, drive a few hundred miles and then refill the tank back to the brim you will never know if you put more or less gas in than you used. Filling it to the brim is the only way you can tell that how much gas you have in your tank when you started, and exactly how much you need to replace for an accurate measurement. You can't use the gas gauge since it's very inaccurate. You can't use the pumps auto shut-off since pumps don't all shut off at the same fuel level...Sometimes too fas a flow will kick off the pump before you have even put in a 1/4 tank.



I have always checked my MPG that way and have never encountered any difficulty and I know my calculations are very accurate. I only check my MPG every 6 months unless I suspect a problem.



...Rich

 

[Gypsy me]

Found this on the net:



Here's why:



Topping off the gas tank can result in your paying for gasoline that is fed back into the station's tanks because your gas tank is full. The gas nozzle automatically clicks off when your gas tank is full. In areas of ozone nonattainment, gas station pumps are equipped with vapor recovery systems that feed back gas vapors into their tanks to prevent vapors from escaping into the air and contributing to air pollution. Any additional gas you try to pump into your tank may be drawn into the vapor line and fed back into the station’s storage tanks.

Gasoline vapors are harmful to breathe. Gasoline vapors contribute to bad ozone days and are a source of toxic air pollutants such as benzene. Evaporation from the spillage of gas from overfilling can occur, contributing to the air pollution problem. Remember you pay for the gas that evaporates or is spilled on the ground.



You need extra room in your gas tank to allow the gasoline to expand. If you top off your tank, the extra gas may evaporate into your vehicle’s vapor collection system. That system may become fouled and will not work properly causing your vehicle to run poorly and have high gas emissions.



Topping off your gas tank may foul the station's vapor recovery system. Adding more gas after the nozzle has automatically shut off can cause the station's vapor recovery system to operate improperly. This contributes to the air pollution problem and may cause the gas pump to fail to work for the next person.



if you would like to read more link provided... and no I'm not GM ha ha

 

[Gypsy me]

Oh, and I found this link too....