SONOMA, Calif. -- JR Hildebrand acknowledged he had to shake off some rust after three months out of an IZOD IndyCar Series car.

“I’m pumped to be back,” the 25-year-old from Sausalito, Calif., said after turning his first laps in the No. 98 Barracuda Racing car during an IZOD IndyCar Series Open Test at Sonoma Raceway on Aug. 21. “As much as anything, it’s just getting back out and getting a feel for things.”

All 25 cars entered in the GoPro Grand Prix of Sonoma on Aug. 23-25 participated in five scheduled hours of testing on the 2.385-mile, 12-turn road course, totaling 1,058 laps without incident.

Dario Franchitti, who has five podium finishes (including the 2009 victory) in seven starts at Sonoma, posted the fastest lap of the day of 1 minute, 18.2945 seconds in the No. 10 Target Chip Ganassi Racing car.

Click it: Morning session results || Combined session results

That lap time was only a second off the the track record set in 2012 qualifications by pole sitter Will Power of Team Penske. Franchitti's teammate, Scott Dixon, was second fast (1:18.3694) and reigning series champion Ryan Hunter-Reay was third on the time sheet (1:18.4707) in the No. 1 DHL Andretti Autosport car.

“It was good to get on the track here at Sonoma and just put into practice a couple of things we think we’ve learned about the car over the past year since we’ve been here," Franchitti said. "It seemed to go well and gives us a good baseline for the weekend. The track conditions are constantly changing here so we have to keep adjusting for it.  If we make good choices and I do a good job behind the wheel, we can hopefully stay up front.”

Power (1:18.5042) was fourth in the No. 12 Verizon Team Penske car, while series championship points leader Helio Castroneves was fifth (1:18.8965).

The top 10 were separated by a second, and the top 24 were separated by less than 2 seconds.

Hildebrand, who won the 2009 Firestone Indy Lights race at Sonoma on the way to the series championship, was the 18th-fastest driver in the session. He said setting quick laps time was secondary to getting accustomed to working with his new team and engineer Todd Malloy.

“I’ve been in the shop with the team and talking through the strategy behind the setups and what I think about the track and my experience and trying to be as prepared as possible,” Hildebrand said. “I feel like we’re off to a reasonable start. The most important thing is to get up to speed on and off track.”

The initial practice session of the race weekend – the series’ ninth visit to the scenic facility – is scheduled for 11 a.m. (local) Aug. 23. The 85-lap race Aug. 25 will be broadcast at 4 p.m. (ET) on NBC Sports Network.

The test served as a chance for Hildebrand to begin building chemistry with Barracuda Racing, which is evaluating its options for next season by fielding Hildebrand and first-year driver Luca Filippi. Hildebrand stopped short of calling this weekend’s race – or his next opportunity with the team at Auto Club Speedway in October – an audition for a 2014 seat.

Hildebrand, who will be making his 40th IZOD IndyCar Series start, has 12 top-10 finishes with a high of second in the 2011 Indianapolis 500. He's made five starts this season with Panther Racing, with a best of fifth at Long Beach after starting 12th.

“This is as much about getting used to being somewhere else and so far, I’ve really enjoyed the environment,” he said. “I think for all of us, we’d like to put a result together. It would be good for me, good for the team. This about all of us getting together and doing a good job.”