In the United States, the Castrol sponsored XJR-9s debuted at the 24 Hours of Daytona, with the car taking the overall win.

In the 1988 World Sports Prototype Championship, the XJR-9, running Silk Cut sponsorship, met with more success.

The XJR-9 was able to take six victories, including the 24 Hours of Le Mans, over the eleven race series.

A similar story occurred in the 1989 World Sports Prototype Championship, with Jaguar not winning a single race during the series.

Within months of Jaguar's 1988 Le Mans victory, TWR would use the XJR-9 chassis for the development of the R9R prototype which by 1990 had evolved into the XJR-15 sports car and spec-racer.