It was explained by Audi engineers: they wanted to develop a turbocharged engine, but due space limitations the supercharged one appeared as better solution ... since turbocharger didn't fit between the engine blocks (like in BMW V8 case) yet supercharger did. So, supercharger was a forced decision ... A not wanted choice. They were forced to develop a supercharged engine - as good as a turbocharged one. Imagine how costly the development was! All the other engines within Volkswagen Group are either NA with FSI, turbocharged, or turbo+supercharged. So this engine was developed for Audi only. Costly ... for VAG criteria.