The Ferrari 512 S had been presented to FIA homologation authorities in January 1970 as a direct answer to the Porsche 917, which had debuted in 1969. While the two cars were considered broadly evenly matched in pace, the Porsche enjoyed superior organisational support through multiple factory-backed satellite teams and proved more reliable over the course of the 1970 championship season. The original 512 S suffered from early-season suspension and transmission problems and struggled with reliability at Le Mans, where all four factory entries retired.
As the season progressed, Ferrari modified a number of 512 S chassis into 512 M specification. The revised bodywork drew on elements similar to those seen on the long-tail Porsche 917, aiming to optimise the car's aerodynamic profile for the high-speed circuits at which Ferrari needed to be most competitive. A distinctive long rear body panel had already been used on standard 512 S cars at fast venues including Le Mans, Spa, Monza, and the Österreichring during the season.
The 512 M's most significant result in factory hands came at the end of 1970, when Jacky Ickx and Ignazio Giunti won the non-championship Kyalami 9 Hours race in South Africa, demonstrating the modified car's improved competitive potential. However, Ferrari chose not to campaign the 512 M as a works entry in the 1971 International Championship for Makes, instead directing factory resources to developing the new 3.0-litre Ferrari 312 PB in response to a forthcoming rules change that would eliminate the 5-litre category after 1971.
In 1971, privateer teams continued to race the 512 M at the highest level. The most notable effort came from the Penske team, which entered an improved 512 M (chassis 1040) in Sunoco livery at Daytona, Sebring, Le Mans, and Watkins Glen. The car was capable of genuine challenge to the Porsche 917, setting pole positions at several American rounds. The primary championship competition for Porsche that season came from Alfa Romeo Tipo 33 entries, though the Penske 512 M demonstrated the modified Ferrari's continued potential.
Several 512 S cars were converted to 512 M specification at various points. Chassis 1020 was converted at the end of 1970 and sold to NART, which raced it in 1971. Chassis 1024, which had remained unsold in 1970, was likewise transformed into a 512 M and sold to Scuderia Brescia Corse. Chassis 1050 was combined with parts from other cars, converted to 512 M form, and campaigned in 1971.
The permit for 5-litre sports cars in the world championship expired after the 1971 season. Some 512 M cars continued in private hands, competing in Can-Am and Interserie races where the regulations still accommodated large-displacement machinery. The factory had by then fully committed to the 312 PB programme for the 1972 World Championship for Makes, which the smaller, lighter 3-litre car ultimately dominated.
The 512 M represents the final development stage of Ferrari's 5-litre Group 4 programme. While it never achieved the championship success of Porsche's 917 in the same era, the 512 S and 512 M established Ferrari's continued commitment to endurance prototype racing after the earlier P-series cars, and the Penske team's 1971 campaign with chassis 1040 demonstrated that the design remained competitive at the highest level even without factory backing. The cars are closely associated with the period widely considered the Golden Age of sports car racing, when the 5-litre machines of Ferrari and Porsche produced some of the most dramatic endurance racing of the twentieth century.