J.W. Automotive Engineering, led by John Wyer and managed by John Horsman, had been building Mirage-branded sports prototypes since 1967. After racing Porsche 917s in 1970 and 1971, the team developed the Ford Cosworth-powered M6 and then the GR7 — renamed to Gulf GR7 in 1974 to reflect the ongoing Gulf Oil sponsorship that had been central to the programme from its very origins.
The GR8 emerged for the 1975 season as an evolution of the GR7 platform, retaining the naturally aspirated Ford Cosworth DFV 3-litre V8 engine that had powered its predecessor. The car competed in the Group 5 Sports Car category and was aimed squarely at Le Mans, where the Mirage programme had consistently featured in the top ten results since 1974.
The high point of the GR8's career came at the 1975 24 Hours of Le Mans. Jacky Ickx and Derek Bell drove their GR8 to an outright victory, claiming the win for the Gulf-Mirage team and for John Wyer's organisation. A second GR8 finished third, crewed by Vern Schuppan and Jean-Pierre Jaussaud, giving the team a dominant one-three result.
The race was notable for an administrative complication: the CSI excluded the 1975 Le Mans from the World Championship for Makes due to new fuel consumption rules that had been introduced for the race in the aftermath of the global oil crisis. Despite this, the victory itself stood as an outright win and remains one of the most significant results in the Mirage story.
Jacky Ickx, already established as one of the greatest Le Mans drivers of his generation, added the GR8 triumph to a remarkable record at the circuit. Derek Bell, who would go on to become a five-time Le Mans winner, claimed his first Le Mans overall victory with this drive. For John Wyer, it was a final crowning achievement before the Gulf Oil sponsorship ended later in 1975 and the team withdrew from competition.
Following Gulf Oil's withdrawal from international sports car racing in late 1975, American entrepreneur and former racing driver Harley Cluxton III purchased the Mirage team along with all associated manufacturing rights from John Wyer and the Gulf Research Racing Company. Cluxton continued the programme, entering GR8s at Le Mans under new sponsorship from JCB Excavators, Elf Lubricants, and Renault Sport, with the continued management of John Horsman and the counsel of John Wyer.
In 1976, Jean-Louis Lafosse and Francois Migault finished second overall at Le Mans in a Cosworth-powered GR8. The following year, 1977, the GR8 was fitted with a Renault 2-litre turbocharged V6 engine to replace the naturally aspirated Cosworth DFV, reflecting the growing influence of turbocharged technology in endurance racing. Vern Schuppan and Jean-Pierre Jarier finished second at Le Mans in 1977 with this Renault-engined variant, again behind a Porsche factory Martini 936.
The decision to adopt the Renault turbo engine was a significant step, as it anticipated the turbo era that would come to dominate Le Mans in the early 1980s. However, the GR8's competitive days were winding down by 1977, and the programme evolved into the M8 and subsequently newer designs.
The Mirage GR8 sits at the heart of what remains one of the most celebrated chapters in Le Mans history. The Gulf-Mirage team, under John Wyer and John Horsman, demonstrated that a relatively small, independently operated team could compete and win at the highest level of sports car racing. Mirage is one of only two independently constructed marques — along with Rondeau — to have won the 24 Hours of Le Mans overall in the post-World War II era.
The 1975 Le Mans victory was the last overall win that Gulf Oil would celebrate at the circuit, making the GR8 the final car to carry those iconic powder blue and marigold colours to a Le Mans triumph. The Gulf livery, first worn by a Mirage M1 in 1967, had in less than a decade become one of the defining visual identities in motorsport history, and the GR8's win ensured that its story ended at the very top.
The car's record across the GR8's Le Mans appearances — one win, two second places from the Renault-engined variant, and a third place at the 1975 race itself — underscores the consistency that the Mirage programme achieved throughout the mid-1970s. Combined with the GR7's second place in the 1974 World Championship for Makes, the GR8 era represented the peak of the Mirage racing endeavour.