SF is really old formula for pre 2006 cars. It was the first generation g12 coolant. Pentosin ++ is far better and is known as G12++ coolant and has silicates. SF was replaced by Pentosin G++ years ago. G++ was just replaced by Pentosin E which is a generation G13 coolant. E is the environmentally friendly version of ++.I have never seen an audi VW mechanic use SF now, when time comes for a flush, they use g12 ++ or G13/ E.Pentosin makes the VAG coolants, they are OEM.