tips on pumping gas

my bro forwarded the below email to me, i didn't verify the content yet, but considering the neverending increase of gas price here in the US, guess it is not bad to post it for your reference (let me know if any of the tips below are proven wrong or just hoax):

Subject: FW: TIPS ON PUMPING GAS

Date: Fri, 7 Mar 2008

TIPS ON PUMPING GASI 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 creat ed while you are pumping. All hoses at the pump have a vapor return. If you are  pumping on the fast rate, some other 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!