2000 A6 4.2L V8 Quattro 88,000 miles. I was told by a repair shop that Audi brake disc rotors are not designed to be turned. They said that they should be replaced, not turned. They claim that the materials used in the Rotors on All German cars, including Audi, BMW etc are made of different material than american or japanese cars and they won't turn them. If they're turned, they claim they will squeel, warp, and lose their ability to perform properly.
Is this True? Seems untrue to me, and simply an 'excuse' to sell me new rotors.
A quick course on modern brake technology. No mater what the tech tells you, metal is metal. That said the real deal is, Manufacturers make rotors and all parts as light as possible for fuel economy standards. Lighter the better lighter=thinner, less to machine! Usually ALL rotors today are throw away!