New York Times correspondent and author of Faster, Higher, Farther, Jack Ewing, tells the inside story of Dieselgate, the Volkswagen emissions scandal — CLEAN DIESEL? In the 1980s at Audi, a young Ferdinand Piëch, later Volkswagen’s chief executive, was working on a technological innovation that would have far-reaching consequences for VW, Audi’s parent company. It was one of the initiatives Piëch was later most proud of: diesel engines designed for passenger cars. Invented…