In the South American country of Guyana where I was born, I would notice on several occasions when going to refuel at the pump station, that the pump attendant would pause pumping the gas, then lean his weight on the vehicle and rock it from side to side.
Needless to say, I wondered what the hell that was for! So I inquired, and I was told that that was done to “free up space” in the gas tank for more gas to go. I was baffled at this point. This logic defied both common sense and everything I had learned about the laws of physics.
Incidentally, I must mention that in Guyana, South America, most of the pump attendants (not all) were high school drop outs and most of them definitely did not pass physics as a subject in school. This was explain a lot. Furthermore, most bus drivers were not science students either, nor were the conductors of the buses, and neither were most hire car drivers. It is easy to see why the practice was perpetuated.
I decided to make a joke about it on Facebook. So I posted a picture of a pump attendant rock the bus and captioned it, “Only in Guyana the pump attendant shakes the vehicle thinking it will free up more space in the gas tank. Ignorance at its finest.”
But I learned from the comments of that post that this practice was not only done in Guyana, but in many other countries around the world. Here are some of the comments the post received.
My parents owned a taxi service. It was my job to ensure all the cars were properly gassed up. And yes, shaking it does free up space. Maybe to allow at least anywhere between $500-$1500 worth in gas. – Jonaton Juman – Guyana
Some idiots in America do dat rass too. – Mark Mosely – USA/Guyana
Duhhh…. its called burping the tank… depending on the shape or angle of your tank if not on level ground….frees up air pockets in your tank to actually hold more gas.