In 1953 the Sports and Stock classes were both subdivided into Large and Small groups, giving four categories in which to compete. These were split by engine cubic capacity; sports cars under and over 1600 cc were Small and Large respectively, and stocks cars under and over 3500 cc likewise. This was to accommodate the huge number of participants and the diverse breeds of cars within the race. This race, like the subsequent running of the Carrera Panamericana was to be the last round of the 1953 World Sportscar Championship season.