???
Maybe worlds most powerful straight six! Audi's new SQ7 TDi beats these figures... and I'm no Audi fan boy(!) but Audi's V6 has BMW beat in these power figures numbers.
"SQ7 TDI comes with 429 horsepower and 663 lb-ft"... two turbos plus one electric compressor!!
http://truckyeah.jalopnik.com/audis-...d-z-1762857083