World Championship for Drivers and Makes
1981
1 February 1981 - Daytona 24 Hours
21 March 1981 - Sebring 12 Hours
26 April 1981 - Riverside 6 Hours
10 May 1981 - Silverstone 6 Hours
24 May 1981 - Nürburgring 1000 Km
14 June 1981 - Le Mans 24 Hours
12 July 1981 - Watkins Glen 6 Hours
16 August 1981 - Mosport 6 Hours
23 August 1981 - Road America 500 Miles
27 September 1981 - Brands Hatch 1000 km