TIPS ON PUMPING GAS (Good information)
I don't know what you guys are paying for gasoline.... but here in California we are also paying higher, up to $3.50 per gallon. But my line of work is in petroleum for about 31 years now, so here are some tricks to get more of your money's worth for every gallon..

Here at the Kinder Morgan Pipeline where I work in San Jose , CA we deliver about 4 million gallons in a 24-hour period thru the pipeline. One day is diesel the next day is jet fuel, and gasoline, regular and premium grades. We have 34-storage tanks here with a total capacity of 16,800,000 gallons.

Only buy or fill up your car or truck in the early morning when the ground temperature is still cold. Remember that all service stations have their storage tanks buried below ground. The colder the ground the more dense the gasoline, when it gets warmer gasoline expands, so buying in the afternoon or in the evening...your gallon is not exactly a gallon. In the petroleum business, the specific gravity and the temperature of the gasoline, diesel and jet fuel, ethanol and other petroleum products plays an important role. A 1-degree rise in temperature is a big deal for this business. But the service stations do not have temperature compensation at the pumps.

When you're filling up do not squeeze the trigger of the nozzle to a fast mode. If you look you will see that the trigger has three (3) stages: low, middle, and high. In slow mode you should be pumping on low speed, thereby minimizing the vapors that are created while you are pumping. All hoses at the pump have a vapor return. If you are pumping on the fast rate, some of the liquid that goes to your tank becomes vapor. Those vapors are being sucked up and back into the underground storage tank so you're getting less worth for your money.

One of the most important tips is to fill up when your gas tank is HALF FULL or HALF EMPTY. The reason for this is, the more gas you have in your tank the less air occupying its empty space. Gasoline evaporates faster than you can imagine. Gasoline storage tanks have an internal floating roof. This roof serves as zero clearance between the gas and the atmosphere, so it minimizes the evaporation. Unlike service stations, here where I work, every truck that we load is temperature compensated so that every gallon is actually the exact amount.

Another reminder, if there is a gasoline truck pumping into the storage tanks when you stop to buy gas, DO NOT fill up--most likely the gasoline is being stirred up as the gas is being delivered, and you might pick up some of the dirt that normally settles on the bottom.

Hope this will help you get the most value for your money.

DO SHARE THESE TIPS WITH OTHERS!

Working at the airport for the last year, I can verify some of the things mentioned here.

First of all, we were always required to verify the specific gravity of the fuel being delivered - because when leaving the dist center a truck may have 4007 gallons pumped, but when actually delivering the fuel load it may get reduced to something like 3950 gallons - and that is what we actually paid for. The trucks usually arrived at the airport at around mid afternoon times, meaning they were leaving the dist center at early morning hours, like 4 and 5 AM - so this tends to support the specific gravity claim - however, the coldest period would more than likely be at sunrise, after a full night of darkness, before the sun has really started to heat the ground up.

The second one makes sense too - the faster the flow, the more it sloshes around in your tank, and the more it is turned into vapor. However, the vapor return going all the way back to the tank seems a little foolish - it seems to make more sense that the vapor return goes only back into the handle, where it is added back to the gas flowing into your tank....

As far as the tank being half empty versus lower, by that rationale, you'd be best filling up every time you used a gallon - or a half gallon - or 1/10 of a gallon. Not sure about this one either.

Finally, as for the stirring up of debris, well, another thing I learned at the airport - we are supposed to pump out the water (yes water gets in the tanks - noting we can do about it) manually every day - it's called chumping the tanks - and along with that it gets the dirt and what not out - and this is to occur only *after* the tank has settled down about 2-3 hours.

If your gas station attendants / truck drivers even bother to sump, they will do it a few hours after the gas has been delivered (and more than likely, again if it is done at all, they will do it at night). So, in these cases you might want to ask if a delivery was made that day, and if so then wait until the next morning to get your fuel. A non-sumped tank is a bad, bad thing for your engine