The long career of the Porsche Turbo started during the first oil crisis--a time when it seemed that fast, powerful cars would have no further place on the motoring scene. Yet the Turbo has remained immune from such criticism ever since its debut at the Paris Motor Show in 1974. The evidence: a quarter of a century of unbroken success. In 1975, when the Turbo went into series production, 260 horsepower were sufficient to put across its power philosophy...