1951 - Radial tyres
This innovation was not specifically invented for the 24 Hours of Le Mans, but the race helped forge its reputation by providing a useful testing ground. In 1951, Michelin fitted a Lancia Aurelia B20 GT with radial tyres, the patent for which had been filed just five years earlier. The introduction of textile cords into the tyre’s carcass strengthened the sidewalls and thus improved solidity and roadholding. Shod with the Michelin X, the Italian car topped the S 2.0 class and finished twelfth overall.
 

1952 - Direct-injection engine
How can performance be boosted while controlling fuel consumption? In 1952, Mercedes introduced a system – originally developed by Bosch for aircraft – that was capable of improving the efficiency of petrol engines. Petrol was injected directly into the combustion chamber, avoiding fuel losses and optimising combustion. The famous 300 SL with gull-wing doors was equipped with this technology when it won in 1952.
 

1953 - Disc brakes
Progress in racing car performance highlighted another necessity: improvements in brake efficiency and endurance. Jaguar discovered the solution when it equipped its C-Types with a revolutionary piece of technology: disc brakes – a solution originally developed for aircraft landing on aircraft carriers! The English make finished first and second in the 1953 race. The idea was subsequently adopted by Citroën on the pioneering DS and is still used today on all production cars.
 

1962 - Quartz iodine headlamps
Around eight hours of the 24-hour race take place at night. Bordered by forest, a large part of the circuit is plunged into absolute darkness. Effective lighting can therefore make all the difference.  In 1962, Ferrari installed halogen headlamps using iodine vapour on the 330 TRI/LM for the very first time. The test proved conclusive as the beam range was doubled and, consequently, halogen headlamps were fitted to all cars from 1965.
 

1963 - Gas turbine engine
In 1957, the constant aim to boost innovation saw the creation of a new class reserved for gas turbine-powered cars. A 25,000-franc prize was offered for exceeding a distance of 3,600 km. In 1963, BRM fielded a strange-looking model powered by a gas turbine engine and fitted with a 220-litre kerosene tank. It attracted a great deal of attention with its whining noise but, as it did not meet regulations, it was not classified. It did however achieve the feat of reaching the finish line in an unofficial seventh place.
 

1967 - Slick tyres
Michelin brought a major innovation to the racing world when it invented “slicks” – tyres with a smooth tread, providing greater traction on a dry track. The results were immediately obvious as the #46 Alpine A210 driven by Vinatier/Bianchi became the first P 1.6 car to lap in under four minutes while winning the class.
 

1967 - Aerodynamic appendages

How can the downforce essential to stability at high speed be increased other than by working on the body design? The answer to this question came from Chapparal who introduced the first rear wing on its 2F prototype. The oversized wing – as wide as the car – looked rather comical as it sat perched high above the rear end. Chapparal had also designed a pedal system to adjust its angle for different parts of the circuit! The active rear wing was born.
 

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