- Nigel Mansell is the only driver to hold F1 and IndyCar titles at the same time
- He pulled off the feat in 1993 after quitting Formula One to drive in the U.S.
- The 60-year-old will be a race steward at this weekend's U.S. Grand Prix
- He says modern F1 drivers are not "crazy enough" to try American cars
"One of the biggest things that I suffered with initially was sickness, especially on the ovals, getting dizzy ... you get out of the car after 10, 15, maybe 20 laps and you couldn't walk straight. I found it very difficult."
Of all the sensations you'd want to feel when driving a car at over 200 mph in front of thousands of spectators, and with the rest of the grid bearing down on your rear wing, it's fair to assume dizziness is not one of them.
Even if you're Nigel Mansell, one of the most successful drivers in motorsport history, and especially not when -- like the Formula One star did when he switched to IndyCar racing in 1993 -- you're plunged into a completely alien environment.
For the Englishman, a rookie acclimatizing to the pressures of racing in one of America's most popular track events, it was the kind of experience where you crave a supportive word or two from a veteran of the scene.
Mansell recalls: "A.J. Foyt was very funny, he said: 'You're in a foreign country, boy, don't turn right -- you'll eat concrete.' And I thought, 'What? Thanks!' A.J. was really fun, lots of very useful tips ..."
Foyt, in 1977, became the first driver to win the Indy 500 four times, and ran his own team after retiring -- but the Texan couldn't match Mansell's unique feat.
Only four men have managed to win titles in both IndyCar and F1, such is the challenge posed by the jump between the two disciplines.
Only one has reigned as champion in both at the same time. Despite his dizziness, Mansell pulled off a remarkable achievement.
Driving the all-conquering Williams FW14B, he was crowned world champion for the first and only time in 1992, having been runner-up the year before -- after coming agonizingly close to the title in 1986 and '87.
However, his glorious 13th season in Formula One ended in his retirement following a dispute with Williams, and he headed across the Atlantic in search of a new challenge.
Mansell accepted an offer by the Newman-Haas team to drive in the CART series. His aggressive driving style, plus the steely resolve forged by his earlier F1 setbacks, helped him take America by storm.
After notching up five wins he took the title and, for three precious weeks, held two of world motorsport's most coveted prizes.
"Winning the IndyCar championship was something incredibly special, it helped to convert the Americans," the 60-year-old told CNN's The Circuit ahead of this weekend's United States Grand Prix.
"I remember, I think it was an NBC television broadcast in Indianapolis the first year I was there, they were really knocking me on television saying, 'Has anyone told this rookie he can't overtake on the outside?'
"And then just as the commentator said it, the other commentator said: 'Well, he's just done it so I guess no-one's told him!"
Mansell, talking at his new museum on the island of Jersey, which sits in the English Channel, has fond memories of his time across the Atlantic -- which was followed by a brief return to F1 with McLaren and a similarly unsuccessful stint in touring cars.
"There were 90,000 fans wishing me happy birthday for my 40th birthday on the race track in New Hampshire," he said.
"We converted a lot of people who wouldn't believe in grand prix drivers in America, and I had a blast and it was fantastic. We've got so many good friends over there, and I think all the sponsors, everybody who looked after us over there, were such great people."
Mansell, who will be one of the race stewards on Sunday in Austin, believes no current F1 driver "is crazy enough" to attempt the switch to IndyCar.
He feels many of them have their talents masked by the technical and tactical nature of the current F1 setup, which has been dominated for the past four years by Sebastian Vettel.
"This is the misunderstanding now, because with the tires they have underneath them, they're not able to 'gorilla' the tires. And now this is a misconception of Vettel and Red Bull," said the former Ferrari driver.
"Vettel is able to set his car in a very, very neutral way and he looks after his tires better than any other car. Predominantly, that's because ... he's a class act. He's four-time world champion, I mean, that's an amazing feat!"
High praise from a man who sold his house to get his first drive, suffered chemical burns in his first race for Lotus and broke his neck and vertebrae in his back in pursuit of his sole F1 title.
"Life and death was almost, well, certainly a monthly thing. Back in the 1960s and '70s, when we started, and then obviously late '70s and early '80s and all through '80s and early '90s, people regularly got seriously hurt and unfortunately died too. So, it was part of the scene.
"What's amazing for me -- if you look at the footage even in the 1990s -- the drivers get out the car half dead, wringing wet, completely expelled of all energy. At Monaco this year, you saw them get out of the car and you think they've just come from the hairdressers!"
Times may have changed but experience like that of Mansell's is seen as a valuable commodity by teams such as Mercedes, which benefits from the wisdom of three-time world champion Niki Lauda -- who is non-executive chairman of the German marque.
"I don't think anybody can afford me, that's the problem," Mansell replied when asked if he could play a similar role.
However, his desire to race still burns strongly.
"As you get old, your body tells you that you can't be there anymore. Although I have to say, with the Red Bull and the British Grand Prix this year, I did put my hat in the ring for the drive," Mansell revealed.
"There'd be certain races I'd definitely be very competitive to win. For a bit of fun I said, 'Please consider me. I'm not over the hill yet,' but I didn't get the call back!"