I have a friend who uses the
amsoil in his cars. He also signed up for the dealer discount thing and he orders cases of
oil and filters at a time. he also buys the spray lubricant like WD-40, it works good too. I have seen the
oil from one of his cars, it had 12,XXX miles on the
oil with a filter change in the middle and the oil looked like it still had plenty of life. In fact, in his acura it had the meter to say when your oil is dirty. it was just barely over 1/2used according to the meter. It could be inaccurate, but I think 12-15k miles is not really unheard of. Everyone I've ever seen that uses
amsoil swears by it! Can't be that bad....
I usually use royal purple since it's a bit easier to find.
Josh