The 1968 24 Hours of Le Mans was the 36th Grand Prix of Endurance, and took place on 28 and 29 September 1968. It was the tenth and final round of the World Sportscar Championship.
The race was originally planned for June 15 and 16, but had to be delayed until September due to massive protests in France during May. The rescheduled race increased the chances of the Prototypes against the Sports, as the new Prototype cars had matured during the season.
Prior to the 1968 race, modifications were made in the run from Maison Blanche to the pit straight, involving the installation of the first Ford chicane to slow speeds along the open pit area. The changes added around 10 seconds to a lap.
In 1968, the rules of sports car racing were changed to reduce speed. Cars with engines larger than 5.0 L were banned from competing in the Sports categories, which was the end for the big block Ford Mk II and Mk IV GT40 and Chevrolet-powered Chaparral at Le Mans. A 3.0 L limit on engines was adopted for the Sports Prototype class, facilitating the use of Formula One motors to save development costs. Cars with up to 5.0 L engines were still allowed to compete in the Sport category if there were at least 50 cars built. This allowed old customer cars like the Ford GT40, the Lola T70 and the Ferrari 275LM to compete against factory prototypes powered by sophisticated 3.0 L engines.
Enzo Ferrari was disappointed to have to take his P4s to the museum and refused to compete for 1968, despite having an F1 engine. John Wyer had to retire his GT40 derived 5.7 L Mirage M1 as well. Wyer chose to dismantle his M1s and to build new GT40s on the Mirage chassis which was close enough to the GT40 to comply with homologation. The Gulf GT40s received some of the improvements of the Mirage, and a significant effort was made to reduce the weight of car using high-tech materials. A large part of the body was made of a very thin polyester sheet reinforced with carbon fibre. Wyer entered 3 GT40s but the team wasn't at its best. Its fastest driver, Jacky Ickx, had broken his leg practicing for the 1968 Canadian Grand Prix, and Brian Redman was still out after breaking his arm in a crash in the 1968 Belgian Grand Prix at Spa.
The competition was between Wyer's Ford GT40 and the new 3.0 L Matra 630, Alpine A220 and Porsche 908. The new 2.0 L Alfa Romeo 33/2 were outsiders.
The Renault-Gordini V8 engine that powered the Alpine A220s was disappointing, giving no more than 300 hp (220 kW). With 350 hp (260 kW), the new 3.0 L air-cooled flat-8 that powered the Porsche 908 was underpowered in comparison to the new Matra V12, but the car was light, had very low drag and the highest top speed. Porsche was much more experienced in Le Mans and had an advantage in numbers, thus Porsche was the favorite.
With Ferrari protesting, the marque was represented only by privateers. The best Ferrari was a green 275LM entered in the Sport category by David Piper. This car was obsolete despite being seriously updated; most of its body was made of polyester/fiberglass instead of aluminium.
Two turbine-powered Howmet TXs were also entered in the prototype class.
The start was given at 15:00 by Fiat boss Gianni Agnelli.
The Porsches began in front. Jo Siffert took the lead on the fourth lap. Then, a litany of minor electric problems slowed the new Porsche 908s, and some were eventually disqualified as the new team management had not studied the rules about repairs properly. Due to the fact that this race was held in late September instead of its traditional time in mid June, there were 5 more night time hours than usual. One of Wyer's cars had clutch failure at 17:00, the other had engine failure at 22:00. By midnight, Wyer had only one car still in race, but it was leading.
Henri Pescarolo had a stunning performance in the new Matra 630. The car started the race with mechanical problems, which sent it down to a 14th place. But Pescarolo drove the car to the second place under the rain, despite a windshield wiper failure and his teammate Johnny Servoz-Gavin refusing to drive the car in such conditions. However, during one of the last pitstops the car caught fire, and could not continue.
The victory went to the GT40 driven by Lucien Bianchi and Pedro Rodríguez. Porsche's best finisher was a private 2.2L Porsche 907 in second, followed by a works 908 in third, both just one lap behind the winning GT40. Alfa Romeo's performance was impressive with three cars finishing, the Nanni Galli/Ignazio Giunti T33 in fourth overall and winner of the 2.0L class. The two other followed as fifth and sixth.
Willy Mairesse suffered career-ending injuries in this race when his GT40 crashed on the first lap on the Mulsanne Straight, and the accident eventually led to him committing suicide.
The race saw the first overall GT class win for the Porsche 911, the platform that would become the most successful GT series in the history of Le Mans.
Failed to cover 70% of the winner's distance (231 laps)Pole Position - #31 Porsche System Engineering - 3:35.40
Fastest Lap - #33 Porsche System Engineering - 3:38.10
Distance - 4452.88 km
Average Speed - 185.536 km/h
Index of Performance - #55 Société des Automobiles Alpine
Index of Thermal Efficiency - #52 Société des Autombiles Alpine