Maybe. Maybe not. It was derided at the other board constantly. Now it's getting a second look.
The pilots I know love AVBLEND, which is what Zmax is.
BMW doesn't endorse it. But there is a TSB that endorses Techron if you don't use Top Tier fuel.
And yes, their dealers sell it in 20oz bottles.
http://www.xoutpost.com/bmw-sa...cleaner-techron.html