Mercedes engaged Sauber to design and run the chassis while the German manufacturer worked to bring the M117 5.0-litre turbocharged V8 to the required level of performance and reliability. Because the C7 already provided a sound Group C platform, Sauber evolved that structure rather than starting from scratch. The principal engineering task was reworking the rear of the chassis to house the bulkier V8 configuration.
The C8 debuted at the 1985 24 Hours of Le Mans, where Sauber qualified the car in seventeenth position — a creditable starting point for a new programme. However, the race ended before it began for the team: John Nielsen suffered an accident on the high-speed Mulsanne Straight, inflicting damage severe enough to prevent the car from taking the start. The team had indicated it would appear at further rounds of the World Sportscar Championship season, but no additional entries materialised in 1985.
For 1986 the programme was restructured and relaunched under the name Kouros Racing Team, entering the full season of the World Sportscar Championship. The opening races showed promise, with results of eighth and ninth place. Two C8s were entered for the 1986 24 Hours of Le Mans, but neither car reached the finish.
The season's defining moment came at the 1000 km of Nürburgring, where Henri Pescarolo and Mike Thackwell drove the C8 to victory. The significance of the win extended beyond points: it was achieved in front of Mercedes-Benz executives who had attended specifically to assess the programme, and it effectively secured the relationship for the seasons ahead. Kouros Racing Team ended the 1986 season fifth in the teams' championship.
When 1987 arrived, the works Kouros effort switched to the more advanced Sauber C9, making the C8 redundant at the front of the programme. The second C8 chassis was sold to a French privateer team run by Noël del Bello, which entered the car at the 1987 24 Hours of Le Mans and the 1000 km of Nürburgring without finishing in either event. Del Bello continued to campaign the C8 through the 1988 season with equally unsuccessful results before the car was retired from competition.
The C8 is historically important as the vehicle that proved the viability of the Sauber–Mercedes alliance, a partnership that would go on to produce the dominant Sauber C9 and then the world-beating Mercedes-Benz C11. The victory at the Nürburgring in 1986 — delivered in front of the right audience at the right moment — gave Mercedes the confidence to escalate its investment and ultimately commit to the all-conquering programme of the late 1980s and early 1990s.