Gas Mileage
According to a story in the Grand Rapids Press, the owner of a small foreign car had begun to irritate his friends by bragging incessantly about his gas mileage. So they decided on a way to get some humor out of his tireless boasting, as well as bring it to an end.
Every day one of them would sneak into the parking lot where the man kept his car and pour a few gallons of gas into the tank. Soon the braggart was recording absolutely phenomenal mileage. He was boasting of getting as much as 90 miles per gallon, and the pranksters took secret delight in his exasperation as he tried to convince people of the truthfulness of his claims. It was even more fun to watch his reaction when they stopped refilling the tank. The poor fellow couldn’t figure out what had happened to his car.
Source unknown.