Grosjean completed 80 laps during the test for the Dale Coyne-Rick Ware team, and was reportedly the slowest of the 12 runners as he adjusted to the new car — but within a second of the day’s fastest lap from Rinus VeeKay.
“It is tough driving those cars, very much, in a different way than Formula 1 where the only thing you fight in Formula 1 is the g-forces where here you actually fight the heaviness of the car physically,” said Grosjean. “But I don’t mind it. It’s quite cool.
“It’s definitely the hardest steering wheel I’ve had to cope with. The first few laps, the muscles weren’t quite warmed up or ready for it. It got better at the end, which is always a good sign.”
Grosjean put his spin down to the difference in how IndyCars and F1 cars perform in fast corners, due to the way that their differentials work.
“I just went too fast in,” he said. “When I was on the brake I also picked up the throttle which you do in high speed, but because it’s a mechanical diff it opens the diff when you do that, and therefore it makes the car lose, whereas in Formula 1 it would actually stabilise the car.