The reason: a series of chain mails that have been zipping through The Great Cloud of Internetdom for months. The version I got a few weeks attempted to argue that gas vapor, cold gas, warm gas, and dirty gas could all be avoided--and could save you money and time. It sounds logical, doesn't it?
Not according to the AAA's Geoff Sundstrom. Most of us are better off paying attention to the running condition of our cars, Sundstrom says: "Consumers would be better served to concentrate on keeping their vehicles maintained, consolidating trips and errands, and adjusting their driving to avoid prolonged idling, hard braking, and sudden acceleration."
So what's true and what's false when it comes to pumping gas? Here's Sundstrom's take on the tips floating around the Web:
1) Only buy or fill up your car or truck in the early morning when the ground temperature is still cold.
It doesn't matter, Sundstrom says. "The idea that gasoline expands when warm and contracts when cold is true," he says, "but the amount of fuel that can be saved by filling up when the temperature is cooler would be so minuscule as to be hardly worth the effort. There is some research taking place in California on the cost to consumers of 'hot fuel,' but conclusive results have not been reported to our knowledge."
2) When you're filling up, do not squeeze the trigger of the nozzle to a fast mode.
Gas can vaporize as it pumps, "but only in extremely small quantities," Sundstrom adds. "The reason the vapor is recovered at the pump is to help limit air pollution from evaporating gasoline. Pumping more slowly may be of some assistance in getting more gasoline for the dollar, but it is not going to alter your fuel bill in any meaningful way."
3) If there is a gasoline truck pumping into the storage tanks when you stop to buy gas, DO NOT fill up.
The warning that there is enough sediment in underground storage tanks that can harm your vehicle is "mostly an outdated idea," Sundstrom says. "Anything that does make its way into the underground tank will be strained out by an internal filter. Your vehicle's engine is further protected by the gas filter in the fuel line."