Just got these tips from one of our engineers...very interesting!
TIPS ON PUMPING GAS Here are some tricks to get more of your money's worth for every gallon.. Only buy or fill up your car or truck in the early morning whenthe ground temperature is still cold. Remember that all service stationshave their storage tanks buried below ground. The colder the ground themore dense the gasoline, when it gets warmer gasoline expands, so buyingin the afternoon or in the evening....your gallon is not exactly agallon. In the petroleum business, the specific gravity and thetemperature of the gasoline, diesel and jet fuel, ethanol and otherpetroleum 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 thepumps. When you're filling up do not squeeze the trigger of the nozzleto 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 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 servicestations, here where I work, every truck that we load is temperaturecompensated so that every gallon is actually the exact amount. Another reminder, if there is a gasoline truck pumping into thestorage tanks when you stop to buy gas, DO NOT fill up--most likely thegasoline is being stirred up as the gas is being delivered, and youmight pick up some of the dirt that normally settles on the bottom.
