I don't know if there's enough information available to deserve a dedicated Audi thread, so mods please delete if you see fit. It does seem that Audi are doing some interesting and unique things though, and I'd like to learn more about it! The gear-ratio chart pictured below was originally posted by AR3-GP, and really sparked my interest.
There have also been rumors that Audi are running a larger diameter turbo than the other engine suppliers, but I don't know how true that is. What is pretty clear is that they are going their own way, and the fact that they look to be quite competitive while doing so is fascinating!