Fernando Alonso became the latest driver to pass through IndyCar's rookie orientation programme on Wednesday, as he prepares to make his debut in the American racing series in the famed Indianapolis 500 race.
The double Formula One world champion, who has been given leave by his McLaren team to miss the Monaco Grand Prix in order to race in the Indy 500, impressed in the first test of his new mount.
Speaking afterwards, Alonso said: "Today was just running alone learning the circuit and all the things that are involved with this technique.
"I am not driving the car, the car is driving myself around at the moment. It felt new to me, it felt a little bit strange driving anti-clockwise at those speeds.
"What I felt in the car was more-or-less what I expected. What is different now is my excitement of the race itself."
McLaren-Honda have partnered with the Andretti team in a one-off deal, with the car wearing a traditional livery – "a nice colour orange, the correct colour orange," as Jenson Button called it, in reference to the McLaren F1 car's more garish colouring.
Button, 37, who drove for McLaren between 2010 and 2016, entered semi-retirement at the end of last season but was kept on contract by the team, who have now recalled him to replace Alonso for the race in Monte Carlo.
A top speed of 222.548 mph is faster than any speed Alonso will experience in an F1 car, though he has raced at the famous Brickyard course previously; half of the oval course was run in reverse, together with an infield section, as the venue of Formula One's US Grand Prix between 2000 and 2007.
The Indy 500 makes up one third of the Triple Crown, together with the 24 Hours of Le Mans and the Formula One Monaco Grand Prix – the last of which Alonso has already won twice. British two-time F1 champion Graham Hill is the only driver to have ever completed the achievement.
Former F1 champion Mario Andretti, father of Andretti Autosport's founder and team principal Michael, said Alonso's willingness to try something new was admirable.
"I commend him for doing this," said Andretti. "I know how he feels because this was always my challenge to go into somebody else's sandbox and see if I could win at their own game.
"There's nothing better than that."
McLaren-Honda are enduring a woefully poor season in Formula One, with their Honda power units markedly low on power compared to rivals.
Alonso, 35 years old and in his third year with the team, has said he is contemplating his future with the team, who have so far failed to revive the glory years of their first partnership with Honda in the Eighties and Nineties.
US marketing guru Zak Brown replaced longstanding McLaren chief Ron Dennis at the tail end of 2016, after the latter was ousted by his fellow shareholders, but an upturn in form has not been forthcoming.