I was doing a little spring cleaning of my personal inbox recently when I came across an email about pumping gas. It was allegedly written by a 31-year veteran of the petroleum industry. I say “allegedly” because it was a forward of a forward of a forward of an email, so who knows where it really originated from.
Anyway, I thought I’d share the little nuggets of wisdom here while I still had it within reach. Take the first tip with a grain of salt since I’ve read elsewhere that time of day & temperature don’t play a significant enough role to matter. Tests were conducted to debunk this, so again it may or may not be valid. The other 3 tips I can see working.
My biggest issue, however, is that I live in NJ where it is technically against state law to pump your own gas. There is no self-serve option here as fuels may only be dispensed by “trained professionals”. (stop laughing!) That law is also the reason our gas is so cheap here – the insurance rates for gas stations is less than other states in the union since we disallow self-serve in favor of these “professionals”. (I said stop laughing!)
Anyway, here are the 4 tips on how to best pump your own gas:
TIME OF DAY MATTERS – 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.
SLOW DOWN – 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. You should be pumping on low mode, 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.
DON’T WAIT UNTIL YOU’RE ALMOST EMPTY – One of the most important tips is to fill up when your gas tank is HALF FULL. 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.
AVOID THE TANKERS – 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.