Actually that was NEVER a myth, it was a fact. When synthetic oil first became available, people switched over to it and sometimes found that a "froth" of oil was created in their engine, and in some cases there was engine damage. Then the synthetic oil industry changed the formula to cure the issue. After that it became ok to switch between conventional and synthetic. Now this response you made to the OP (original poster) is a bit of a slam, and you should know you missed the point. Synthetic oil molecules are smaller than conventional oil, and because of this the synthetic oil "slips" out of the engine of older cars with over 100K miles much more quickly than conventional oil. It sneaks past the seals and rings much more easily and ends up forcing you to add more oil more often between oil changes... or risk not realizing that your oil is low and blowing up your engine. So as the OP has noted, it's has indeed become hard to find conventional oil in certain places in the USA. I am concerned since I'm now out of my last batch of 5 qt containers of conventional, and need to change the oil in both my cars which are nearing 200K miles. Im going to try the synthetic blend and hope that i'm not spending more time adding oil between oil changes than normal (usually 1 qt mid way between oil changes). I have noticed as others have pointed out that the synthetic blend oil is just about the same price as the conventional oil I used to buy. But again, my concern isnt money, its waste of oil and the possibility of me not realizing im low on oil.. and causing engine damage. I drive my cars until they are done even though I could get a new car every 3 to 5 years like so many people. I like to conserve resources, and my money too!