It's something people pull out because they've heard stories on the internet, not experienced the real thing. Before the early '70's vehicles of all sorts from all manufacturers leaked oil....until oil became an HC for emission control, there was no need to control oil leaks. Road tubes, labyrinth and rope rear mains, they are the oil leaks, and even the Japanese used them. My 1938 Chev used to do 100 mpg...on oil...standing still.