You should not pour cooking oil in someone's gas tank.
Dave and his friends are thinking of practical jokes to play on their friend Tom.
Dave wants to suggest something they can do to Tom's car.
Dave suggests writing funny messages on Tom's car windows.
"Dave suggests pouring some cooking oil into Tom's gas tank, then placing a funny note telling Tom about the ""fill-up""."
Tom sees the messages and has a good laugh about them.
Tom has to drain the gas tank and get it cleaned out so the car can work properly.