Amsoil is excellent stuff, check out this story hehe. My freind had an old dodge pickup, he believed when the oil was low he'd fill her up and that would be his oil change after like 6-7 fills. Well one day i convinced him to really change his oil, and better yet with amsoil. So he did. WOW, lol, the synthetic blend broke down all the sludge and grime he had built up for 180,000 miles, clogged the oil pump, and started creating leaks everywhere!!! Within 8 hours of the oil change this all happened, the sludge used to block the small leaks and seal them from leaking, well when the amsoil ate through it, wala, leaks leaks leaks. Needless to say he trashed the truck and swore to me once more "If it aint broke dont fix it" lol i still hear about it today and that was 6 years ago...