The IndyCar Series drivers were highly impressed by the crowd drawn to the first day of the two-day open test at Barber Motorsports Park, near Birmingham, Alabama.
Reigning champion Scott Dixon's 1m10.5005s lap was the fastest of the day around the 15 turn, 2.3-mile road course, but the most striking number was Sunday's spectator count of 10,300, according to the circuit.
"It reminds me of when we used to go testing in Spain when I was in F1," said Ryan Briscoe, a former Formula 1 test driver for Toyota. "I've never seen it over here like this. It's pretty cool."
The strong attendance was the result of extensive promotion by track officials, who have expressed interest in attracting an IndyCar race. The fact that Indycars drew a small but enthusiastic crowd for a test session in the heart of NASCAR country during a NASCAR race weekend drew a positive response from the participants.
"People want to come out and see us race," Briscoe said. "We're the fastest form of motor racing in America, and it's always fascinating to see speed.
"It's certainly been a lot of fun out here. I've been signing autographs and having my picture taken between sessions. That's something we definitely can't say we've ever done on test days."
Built in 2003 by Birmingham dairy owner George Barber to go with his vintage racing museum, and designed primarily for sportscar and motorcycle racing, the Barber circuit features wide-ranging topography, sweeping turns and long straights that reminded some of Mid-Ohio and Infineon - although Dixon felt it was unlike anywhere else on the schedule.
"It's a fantastic circuit," Dixon said. "It's got a lot of elevation changes and is quite flowing. It's very different from a lot of the places we go to.
"It's very smooth, but has bumps and character in different areas. Because it's quite flowing, I think it would be difficult to pass. But there are changes they could make to alleviate that."