This is the first ever book devoted exclusively to these six-cylinder ACs. In 1919 the small English firm of AC Cars came out with a new engine which, amazingly, was to power their products for more than 40 years. It was a six-cylinder unit with alloy block, cast-iron wet liners and a single overhead camshaft. The author opens with a review of the company’s products prior to the introduction of the 16/66 model in 1933. He goes on to give highly detailed descriptions of all models and variants - 16/70, 16/80, 16/90, and the post-war Ace, Aceca and Greyhound - covering every aspect of the chassis, running gear, engines and transmissions, and discusses the changes made to specifications and equipment during production. The history of the cars in competition is studied, and the author also advises on the practicalities of owning any of these models today, including common problems, parts availability, maintenance and preservation. There are also more than 150 black-and-white photographs from archive sources.