Mansell has eclipsed his team-mate, Mario Andretti, from the first day he arrived two years ago. But it is Andretti's last race of his career, and that has overshadowed Mansell's finale, the Arrivederci Mario tour having reached a fevered pitch.
With all that Mansell has contributed to the PPG IndyCar World Series, there remain people who resent his dominance and who have never quite accepted him. It did not help that Mansell took so naturally to ovals. Mansell described that uniquely American form as 'pure racing'. He adapted his own style to the ovals and blew everyone's doors off.
Mansell has been outspoken, occasionally saying things that needed to be said. Among many fans and participants, there has been a love-hate relationship with him from the beginning. Undeniably he has provided some of the most exciting racing ever seen here. Perhaps the most memorable show was at Cleveland last year when Mansell went wheel to wheel with Emerson Fittipaldi, trading positions seven times in four laps. Even Mansell's most adamant detractors grudgingly admit he is a brilliant driver, in a class by himself.
Among the elite of racing, Mansell probably enjoys meeting the fans more than anyone. He devotes long stretches of time to signing autographs and talking with fans. Team sponsors have marvelled at his willingness to make personal appearances on their behalf away from the race track.
Mansell has enjoyed the past two years of racing immensely, even though the near perfection of the Penske chassis and some incredible bad luck have conspired to thwart his ambitions this season.
The Newman/Haas team manager, Jim McGee, compared Mansell's fairytale rookie year to his present winless streak, reflecting Mansell's own philosophical acceptance of a wretched run. 'Several times last year we got a good break,' McGee said. 'Then there are years like this year when none of the breaks go your way.'
McGee added that Mansell has been just as competitive this year and his motivation just as high. The list of bad breaks seems endless: twice, when he has been disputing the lead, his tyre has gone down after being hit from behind; leading the race at Michigan, a valve in the engine broke; and twice more in contention for the lead, he stalled in the pits because of problems with the Cosworth engine-management programme.
McGee said: 'When Nigel leaves it is going to be a big loss. When he came over here, he was a big supporter of IndyCar racing. He enjoyed racing here and he brought worldwide attention to the series.'
Has Nigel Mansell made a difference to IndyCar? He made history here and set records that will be difficult - some nearly impossible - to break. We are not likely to see a reigning Formula One champion defect to IndyCars again, and even less likely to see any driver claim the PPG Cup in his rookie year.
Will Mansell return for an encore? The one laurel Mansell has not claimed is a win at the Indianapolis 500. He has been very competitive at Indy, and it was only his inexperience with the rolling starts that robbed him of a victory in his first year.
Mansell will not comment on whether he is even interested in racing at Indy again. But in his own, now prophetic words, 'Anything is possible in motor racing'.