The 1975 24 Hours of Le Mans was the 43rd Grand Prix of Endurance, and took place on 14 and 15 June 1975.
In the wake of the 1973 oil crisis, the ACO demanded a maximum fuel consumption of 40 liter per 100 km,les organisateurs imposent une consommation maximale de 40 litres aux 100 km. - https://www.24h-lemans.com/fr/actualites/il-y-a-40-ans-les-24-heures-du-mans-1975-20610 and with different rules, the 24h was not part of the 1975 World Sportscar Championship. Colloquially called the “Le Mans Economy Run”,Spurring 2011, p.171Clausager 1982, p.167-9Clarke 1997, p.10: Motorsport July 1975 stringent refuelling regulations were put in place. Claiming to be unable to match the requisite fuel economy, the Willi Kauhsen Racing Team-entered semi-works Alfa Romeo T33TT12 that dominated the 1975 WSC season remained absent. Matra, three-time winner since 1972, had retired from the sport at the end of 1974, Ferrari had quit already after 1973. Porsche, who had brought a turbo-powered Carrera in 1974, waited until the new WSC rules with two championships came in effect, postponed to 1976. Therefore, in the above 2 liter sportscar category that was favorite for the overall win, this only left Mirage, renamed after sponsor Gulf Oil, and Ligier as front-running works-teams. Both used detuned versions of the 3 liter V8 Cosworth DFV F1 engine which scored its first Le Mans win (the second came in 1980). Two other oil companies, Elf and Esso, supported smaller sportscars with all-female drivers.
The race was won by Jacky Ickx and Derek Bell in their Gulf GR-8, finishing just a lap ahead of the Ligier of Jean-Louis Lafosse and Guy Chasseuil. It was the first victory for an all-British car since the Aston Martin in 1959, and for running at an ‘economic’ speed, the winner covered just one lap less than the winning car of the previous year.Clausager 1982, p.167-9
Regulations The ongoing fuel-crisis was having a growing impact on international motor-racing, as critics saw the sport as a profligate waste of petrol. The Automobile Club de l'Ouest (ACO), ever wanting to follow its original mandate to advance automobile technology,Clausager 1982, p.24 put in radical measures to provide a solution. All cars had to go 20 laps before refuelling with petrol and oil – roughly equivalent to , around 7mpg, for a 25% improvement.Clausager 1982, p.167-9 As a reference, the Matras had only done 16 laps between their fuel stops in 1974.Spurring 2011, p.174 Fuel tank sizes were also limited in size.Clausager 1982, p.167-9
These, however, put it out of step with the CSI (Commission Sportive Internationale - the FIA’s regulations body) and the FIA therefore removed the Le Mans 24 Hours from the World Championship calendar. This had happened before when the FIA had excluded Le Mans in 1956 because of their stricter safety requirements after the 1955 disaster.Clausager 1982, p.167-9Wimpffen 2007, p.158 It can also be pointed out that Le Mans races prior to 1960 had run to refuelling restrictions.Clausager 1982, p.167-9 For its part, the CSI had postponed the introduction of its new Group 5 “silhouette” rules until 1976.Spurring 2011, p.180
The ACO also introduced a new “GTX” (Le Mans Grand Touring Experimental) class for GT cars to use non-homologated equipment like the brand new Porsche 930 turbo. It also opened up its entry list to Group 3 GTs, alongside the Group 5, 4 and 2 cars. Finally, the ACO allowed teams to replace any pieces of equipment during the race, but the defective parts had to be given to the ACO technical team.Spurring 2011, p.174Clarke 1997, p.7-8: Autocar Jun21 1975 This year, the ACO also gave a prize to the car which used the smallest amount of fuel. Also the Index of Thermal Efficiency was now opened to all car classes.Spurring 2011, p.9
Since the race's inception in 1923, the Le Mans circuit had incorporated using public highways. An ambitious plan in the early 1970s had been proposed to build a new Mulsanne Straight parallel to the main road and bypassing the Mulsanne corner.Clausager 1982, p.23 However, by 1975 with the economic recession and reduced interest in motor-racing, no work had been started, and in the end the project was cancelled later in the year.
Entries To general surprise, the ACO received a commendable 101 applications, which became 71 arriving for qualifying and a final 55 in the race.Spurring 2011, p.173 However, Matra had followed Ferrari out of Sports-Car racing. Alfa Romeo works team Autodelta had sold its cars to German Willi Kauhsen,Wimpffen 2007, p.158 who chose not to enter, saying there was no way the Alfas could make the necessary fuel economy. Alpine-Renault cited the same reason.
Category Sports-PrototypeGroup 5 GT ExperimentalGTX Special GTGroup 4 Production GTGroup 3 Special TouringGroup 2 TotalEntries Large-engines >2.0L classes13 / 11 4 / 127 / 22 9 / 7 7 / 560 / 46 Medium-engines < 2.0L classes11 / 9000011 / 9 Note: The first number is the number of arrivals, the second the number who started.
Although John Wyer had semi-retired, he saw an opportunity for his Gulf-Mirage cars with the fuel-formula and the lack of big opposition. Last year the Gulfs had achieved fuel consumption of 6.1mpg.Clarke 1997, p.6: Autocar Jun14 1975 So he and JWA designer John Horsman set about adapting and optimising a new model, the Gulf GR-8 for this single race in the season. It had a long-wheelbase and low-drag body. They detuned the Cosworth DFV to run at a 8400rpm rev-limit, down about 2000rpm.Spurring 2011, p.176-7Clarke 1997, p.17-8: Autosport Jun19 1975 The engine would now put out 380 bhp capable of 310 kp/h (195 mph). Chemists at Gulf Oil developed a fuel for the cars and put together they could achieve an impressive 7.25mpg.Spurring 2011, p.176-7 Once again, Wyer was able to call upon Jacky Ickx to drive, partnered with Derek Bell, while the other car had Vern Schuppan and Jean-Pierre Jaussaud.
In the absence of other manufacturers, it was Guy Ligier who would be Gulf's biggest competition. Suffering from the effects of the economic downturn, Ligier realised he would not have sufficient cars built to get Group 4 homologation. Having purchased the facilities of the defunct Matra Sport at the end of 1974, Ligier was preparing to enter Formula One. With the services of Matra's engineer Gérard Ducarouge and ace driver Henri Pescarolo he also adapted his JS2 cars to carry the Cosworth DFV engine (detuned to about 410 bhp) and Hewland gearboxes. However, being about 10% heavier than the Gulfs meant the Ligiers were slightly slower in a straight line. For the race, regular drivers François Migault and Jean-Louis Lafosse were split: Migault drove with Pescarolo, while Lafosse teamed up with Ligier-regular Guy Chasseuil. As a late entry, the team also ran a 320 bhp Maserati-engined version for two other former Matra drivers, Jean-Pierre Beltoise and Jean-Pierre Jarier.Spurring 2011, p.178
Meanwhile, in the World Championship, it had been the five-year old,Clarke 1997, p.13-4: Motor Jun21 1975 360 bhp Porsche 908/03 of Joest Racing taking the battle to Willi Kauhsen's Alfa Romeos. Norbert Singer, Porsche works engineer, was seconded to the team and gave the car a longtail chassis. Team-owner Reinhold Joest drove with Mario Casoni and Jürgen Barth.Spurring 2011, p.180 British privateer Alain de Cadenet arrived with a new car – a Lola T380 fitted with a Cosworth DFV capable of 400 bhp by engine-specialist John Nicholson. Despite this the chassis was very new, and nearly 40 kp/h slower on the straights than the Gulfs and Ligiers. It was driven by regular racing duo of de Cadenet with Chris Craft.Spurring 2011, p.187 Swiss privateer Heinz Schulthess likewise entered a new Lola-Cosworth T284, tuned by another engine-specialist, compatriot Heini Mader.Spurring 2011, p.191 Shin Kato returned with his latest Sigma model, the MC-75, that was now powered by a 1.6-litre Toyota turbo engine which put it in the 3-litre class because of the x1.4 equivalency factor for turbo enginesSpurring 2011, p.84Spurring 2011, p.191 (in sports car racing, the factor in Formula 1 was x2.0Automobile Year 1976, p.145).
The fuel-economy regulations now made S-2000 class a lot more competitive. Renault Sport had won the inaugural 1973 World Rally Championship, and was now focused on Sports-car racing.Spurring 2011, p.182-3 Along with its subsidiary companies Gordini (engines) and Alpine (chassis) had been working on a new sports car. For 1975, the new turbo-powered A442 made an immediate impression beating the Alfa Romeos at Mugello. However their cars were very new and proved fast but unreliable. The works team did not enter, however a non-turbo, A441 arrived in the colours of Elf Switzerland for the all-female team of Marie-Claude Beaumont and Lella Lombardi.Spurring 2011, p.182-3 It was the first Alpine to race at Le mans for six years.Clausager 1982, p.167-9 André Moynet, French war hero, politician and amateur racer, had been building his own sports car, based on a Chappe et Gesselin chassis with a 2-litre Simca-JRD engine and Porsche transmission. He gained sponsorship from Elf's competitor Esso-France, who suggested also compiling an all-female driving team. Moynet hired Michèle Mouton, Christine Dacremont and Marianne Hoepfner for his car.Spurring 2011, p.184
The strong showing by the new 2-litre Simca-ROC engines in the 1974 race saw five cars with Fred Stadler's engine including three Lolas of his own team.Spurring 2011, p.190
In lieu of the works team, Ferrari was represented primarily by the North American Racing Team (NART) bringing four different cars in three categories. The 308 special returned in Group 5, and a regular 365 GTB/4 for Ronnie Bucknum/Carlo Facetti in Group 4. The other two were entered in the new GTX category: a new 365 Berlinetta Boxer and a 365 Daytona spyder.Spurring 2011, p.186
The Group 4 Special GT class was dominated by the Porsche RSR teams. This year's most successful team - Georg Loos’ Gelo Racing - had three cars entered, for John Fitzpatrick (the current European GT champion)/Gijs van Lennep, Tim Schenken / Howden Ganley and Toine Hezemans/Manfred Schurti. Their main competition came from their compatriot Kremer Racing and Tebernum teams (supported by Joest Racing), the Swiss Porsche Club Romand, Spanish Escuderia Montjuïch along with the local French ASA Cachia-Bondy team and owner-engineers Robert Buchet and Louis Meznarie.Spurring 2011, p.181-2
Up against the armada of 911s (comprising half the field with 28 of 55 starters) alongside the NART Ferrari, were two other 365s for the Ecurie Francorchamps and French privateer Marcel Mignot.Spurring 2011, p.186 Along with Henri Greder's Chevrolet Corvette was also a De Tomaso Pantera and a Datsun 240Z. As expected, Porsche dominated the new Group 3 entry with eight of the nine cars against Wicky Racing's lone De Tomaso Pantera.
There was renewed interest in Group 2 this year, with seven cars arriving for qualification. These included two Ford Capris from the French Shark Team and the return of Claude Buchet's Mazda twin-rotary RX-3. Against them were three BMWs: defending class-winner Jean-Claude Aubriet brought his 3.0 CSL back. Lichtenstein engine-specialist Max Heidegger prepared a BMW 2002 TI with a F2 engine (capable of 260 bhp) for French privateer Daniel Brillat.Spurring 2011, p.189 The third was another French privateer. Hervé Poulain, an art dealer and keen racer, entered another 3.0 CSL and convinced his friend, artist Alexander Calder, to paint it. Although not the first “art car” (Porsche had raced the psychedelic Martini-917 in 1970 and “Pink Pig” in 1971), it was to become the first of many BMW Art Cars. BMW insured it for DM 1 million (~US$430 000),Clarke 1997, p.11: Road&Track Oct 1975 and Poulain got 1964-winner Jean Guichet and American IMSA-BMW driver Sam Posey as co-drivers.Spurring 2011, p.188