Ferdinand Piëch, a scion of the Porsche carmaking family who led Volkswagen for two decades marked by rapid international expansion but also by scandal, died on Sunday in Rosenheim, a city in Bavaria. He was 82.

Mr. Piëch’s wife, Ursula Piëch, said in a statement that he died “suddenly and unexpectedly” but did not give a cause. German news media reported that Mr. Piëch collapsed in a restaurant.

Along with his grandfather, Ferdinand Porsche, the designer of the Volkswagen Beetle, Mr. Piëch ranked among the most influential car executives of the last century. Under his leadership Volkswagen became the largest car company in Europe by a wide margin and rivaled Toyota for the title of largest automaker in the world.

Mr. Piëch was also a notoriously demanding boss who ran Volkswagen like a personal fief. His record of firing or demoting executives who failed to meet his goals, and his apparent tolerance for questionable behavior, led to criticism that he created the authoritarian company culture that bred a costly emissions cheating scandal.