Ron, I've heard this too. I've also heard that you should never, ever put synthetic oil into an old engine that's always had regular, mineral-based oil. Like you said, synthetic oil is so thin, it can find little gaps and holes. Only use synthetic oil on a car that is fairly new, that is, about 12000 miles or less. But yes, synthetic oil is superior to mineral-based oil, won't gel up on cold winter mornings or turn to the consistency of water during scalding hot summers.