Heuer has always been closely tied to the world of motorsports, especially Formula 1 Grand Prix. During the exciting racing era of the 1960’s and 1970’s, most drivers had Heuer watches on their wrist, including champion driver Jo Siffert. Witnessed on the wrist of the Swiss Double Formula 1 Grand Prix champion during races, was a Heuer Autavia reference 1136 featuring a tachymeter scale on a white dial with black subsidiary dials and a date. Following the tragic accident in the 1971 Grand Prix, Heuer released the reference 73663 with what is now called the “Jo Siffert” colors.