During Lotus and Clark used three completely different cars and engines. The Lotus 43 performed poorly at the opening South African Grand Prix, so Clark used an old Lotus 33 at the following Monaco Grand Prix, retiring with suspension failure. Lotus then began its fruitful association with Ford-Cosworth. Their first car, the Lotus 49 featuring the most successful F1 engine in history, the Ford-Cosworth DFV, won its first race at the Dutch Grand Prix, driven by Clark. He won with it again at the British, United States and Mexican Grands Prix; and, in January 1968, at the South African Grand Prix.