I have a few questions on the A4 brakes, specifically 2005.

First question: what is the factory friction material? Is it Semi-Metallic or Ceramic? According to RockAuto.com, Semi-Metallic is OEM.

#2: Who makes the OEM brakes? I was looking on ECStuning at the OEM brakes and you can clearly see Akebono stamped on one of the ears. Rockauto also says that they are the OEM supplier.

I was tying to do some research and there was somewhere that said after a certain year, Audi went to ceramic brakes instead of Semi-Metallic. Is that the case?

 

On my 2008 they were semi-metallic. There is some debate what is OE and what is OEM. To me OE is what came from the factory while OEM is made to the same specis as what came from the factory. In other words if Akebono supplied some OE brakes then brakes bought from them (not through Audi) would be OEM. OEM to means as good if not better than factory.

Wouldn't be surprised if the S4 had ceramic brakses and possible some of the newer model A4s as well. Less brake dust with ceramic.