No one has ever achieved the feat of being Formula One World Champion AND IndyCar Champion at the same time, except one man - Nigel Mansell. And here’s how he did it.
Only three other drivers managed to reign both series and all of them come close to being or just simply are stuff of legend - Mario Andretti, Emerson Fittipaldi and Jacques Villeneuve, but Mansell was the only one winning the two championships back to back, resulting in being champion at both at once with the 1993 F1 World Championship not being decided yet by the time he already won the IndyCar title the same year.
Frank Williams is not an easy man to deal with, nor Nigel Mansell. Together they were like mixing two different, highly explosive material. Still, both are quite magnificent in their own way, which ultimately lead to Mansell winning the 1992 Formula One World Championship with the team (helped by the super-gizmo active suspension system) after having spent 12 years in the series. But push comes to shove, the two people eventually fell out and Mansell left Williams’ team as the latter wished to sign Alain Prost as his team mate. These two have already been together at Ferrari in 1990 and having had a quite strained relationship back then, Mansell decided to bow out. [Note: Ironically, after Prost joined Williams and won the championship in 1993, he, too, left Williams for the same reason as Senna was signed for 1994. Their earlier, stressful relationship at McLaren is widely documented and is one of the most cited periods of all F1's history.]