Jasmine: Hi, I'm Jasmine.
Chrissy: I'm Chrissy.
Jasmine: We're from NIU STEAM and...
Chrissy: You're listening to The Sound of Science on WNIJ.
Jasmine: At a recent STEAM event, a guest posed the question about whether the speed at which you pumped gas changed the volume of gas that you were able to pump. This is a great question as travel increases for the holiday season!
Chrissy: Gasoline is classified as a volatile liquid, which means that it changes states of matter very easily from a liquid to a gas. It has a very low boiling point and evaporates very quickly. These vapors are what make gasoline extremely flammable and toxic.
Jasmine: In 2000, the EPA mandated that gas stations selling 1,000 gallons or more of gas per month install Vapor Recovery Systems in their pumps. These systems capture gasoline vapor during dispensing, preventing air pollution and allowing the vapor to be returned to the storage tank, which conserves gasoline.
Chrissy: There is a good deal of debate surrounding this topic. Gasoline vapor is at the heart of the argument for those that feel that dispensing speed affects the volume of actual fuel that reaches your gas tank. It is believed that faster pumping speeds increase vapor volume, meaning you might pay for vapor that is recovered and never reaches the tank. A slower dispensing rate allows more fuel to remain in liquid form, ensuring it enters your car as fuel, ultimately increasing volume.
Jasmine: Others argue that in modern gas pumps, fuel volume remains constant regardless of pump speed, claiming that pumps dispense at a fixed rate of 10-20 gallons per minute. This calibration makes vapor recovery differences negligible. Slower pumping simply means it takes longer to fill your tank, resulting in more time spent at the gas station.
Chrissy: You have been listening to The Sound of Science on WNIJ, where you learn something new every day.
