He's an Amsoil dealer, and Amsoil claims to be so superior that it's properties don't break down, allowing for longer intervals between oil changes. The only problem with that is the contamination that exisists thanks to burning gasoline (as well as the gas that doesn't burn and gets by the rings) stays with the oil. No oil should be used for more than 5k miles. I personally change mine every 3k miles.
Take care,
-Chris