The 1965 24 Hours of Le Mans was the 33rd Grand Prix of Endurance, and took place on 19 and 20 June 1965. It was also the twelfth round of the World Sportscar Championship.
For the 1965 season, the development and racing of the Ford GT40 was entrusted to Carroll Shelby. On Shelby's initiative, the GT40s were fitted with the same engine as the Cobras — an iron cast 4.7 L V8, and the Colotti gearbox that proved unreliable was replaced by a German-made ZF.
In parallel, Ford developed a new version of the GT40. The Mark II was developed by Ford subsidiary Kar Kraft in Dearborn under the direction of Roy Lunn. The Mk IIs were powered by a 7.0 L engine based on a Ford Galaxie block. As there was no gearbox available on the market which was able to sustain the torque, the car featured a new 4-ratio Kar Kraft gearbox. Two Mark IIs were entered by Shelby. The cars were finished in a hurry; as there was no time to run a fuel consumption test, Shelby did not know the real fuel consumption of the 7.0 L Mk II.
Scuderia Ferrari entered two P2s, a new version of the prototype, featuring a new DOHC V12 engine. Strangely, Ferrari dispersed some of his effort by entering a 1.6 L Dino 166. Two 365 P2s were also entered, one by NART, the other by Maranello Concessionaires. The 365 P2 was built around a previous year's P chassis with updated aerodynamics and featured a 4.4 L SOHC V12.
Several 275LM prototypes were entered by Ferrari customers. Ferrari developed the mid-engined LM for homologation in the GT category but was refused by the CSI. These cars are often mistakenly designated as 250LMs, as the first car built was fitted with a 3.0 L engine. The cars delivered to customers were 275LM powered by a 3.3 L. The performance of the 275LM was far from "real" prototypes but as the engine was a close derivative of production Ferrari engines, the car had proved very reliable.
The Mark IIs took the lead at the start, but lost a part of their advance in frequent refuelling. It would later appear that the Mark IIs refuelled more often than required due to the uncertainty of their fuel consumption. The weather was hot, and overheating began to hit the GT40s. Bob Bondurant and Umberto Maglioli's No. 7 had head gasket failure before 20:00 and on the same lap, Herbert Müller and Ronnie Bucknum's No. 6 overheated terminally.
After the failure of the Fords, four Ferraris were leading. By then, the top Ford-powered car was the Dan Gurney/Jerry Grant Cobra Daytona coupe. Around midnight, Gurney and Grant had risen to third overall. That was when the Cobra's motor mounts began to crack and Gurney had to park the blue coupe after 204 laps.
This left the Ferraris on top, but the P2 began to suffer excessive disk brake wear, probably due to heat. All the leading prototypes had pit stops to change disk brakes, an operation that required between 20 and 30 minutes.
As the 275LMs put less stress on the brakes, two of them were leading at 04:00; Pierre Dumay's Belgian yellow car led the NART 275LM of Jochen Rindt and Masten Gregory. The NART Ferrari had lost time struggling with ignition problem, but now the engine was sounding clear and the car gained several second on each lap. Soon after 13:00, the Belgian Ferrari had approximately one minute over the American one, but Rindt was driving 12 seconds per lap faster. As the leader needed only one refueling stop to finish the race while the NART car would have to stop twice, a close finish was expected.
Then, a tire began to deflate on the leading car, and soon disintegrated, destroying a large part of the thin aluminum rear bodywork. It took the Belgian team five laps to have the car ready to rejoin the race. This was more than enough to give the victory to Rindt/Gregory. Ed Hugus, the relief driver, declared many years later that he actually drove a whole session in the LM when Rindt couldn't be found while sleeping somewhere during Gregory's drive, but his drive was not credited because -according to regulations- Gregory would be not allowed to drive again the car once Hugus replaced him (while he actually did) and the car should be disqualified, but no one officially recorded this. Hugus never made public claims on this story, which was revealed only in late 2000s, when after his death one of his fans made public a letter written to him by the pilot giving all the details.