6 pistons.

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Audi was founded by August Horch in 1899 as A Horch Automobile Company. Later, he had disagreements with his partners and founded August Horch Automobile Company. However, the company was dismissed because of the same company name. Accused, so the company name was changed to the Latin word Audi of Horch (German for hearing). Audi's trademark "four rings" originated from the four companies in its early days (in mainland China, Audi cars were also nicknamed "tetracyclines" for this reason). In 1932, the four major German car manufacturers Audi, DKW, Horch and Wanderer merged into "Auto Union" (Auto Union), and hired Ferdinand Porsche to design the Auto Union V16 racing car (also known as Silver Arrow), and led its team to win the right to represent Germany from the Mercedes-Benz team, and then defeated the world in the European continent Invincible hand.