This decade at Le Mans began with the first victories by Porsche, whose awesome 917 racing car, capable of more than 240mph (385kph), established a distance record that would stand for almost four decades. One of a hat-trick of wins by Matra, effectively the French national team, was achieved in a famously frantic, head-to-head duel with Ferrari. In 1975, the oil crisis led the ACO to run its race to a 'fuel formula', and it was won by the Ford-supported Gulf-Mirage team. Porsche, using motorsport to develop its turbocharging technology, won again in 1976 and in 1977, when Jacky Ickx produced one of the greatest drives ever seen in motor racing anywhere. A massive effort by Renault, again with a turbocharged engine, delivered success in 1978. The decade closed, as it had started, with a soaking wet race that was won by Porsche. This 10-year chronicle describes events as they unfolded during each of the races. The reader will learn about the ever-changing regulations - many introduced to encourage fuel efficiency - that governed the races, and follow the technical advances made by innovative competitors as they strove to win the biggest prize in motor racing.