INDIANAPOLIS — No matter their experience at other tracks, all drivers who race in the Indianapolis 500 for the first time are considered rookies.

So drivers such as Oriol Servia, Justin Wilson and Will Power were required to take part in the annual Rookie Orientation Program that began Sunday. Servia made 125 starts in the former Champ Car series and once tried to qualify at Indy, while Wilson had four wins among his 54 Champ Car starts. Power was the Champ Car rookie of the year in 2006 and won that series' final race last week at Long Beach, Calif.

Ten of the 12 rookies completed all four phases of their test, led by Power with a top lap at 220.604 mph, E.J. Viso at 220.445 and Servia, Power's teammate at KV Racing, at 220.102. The only veteran on the track was Max Papis, who hasn't driven an Indy car in two years and was required to take a refresher test.

"It was a good day," said Power, a 27-year-old Australian who also had two Champ Car wins last year. "We crept up to it; we had a pretty solid car. I was happy to get flat all the way around. ... Now the challenge starts. When you start trimming out, that's when the driving really comes in. You have to be smart with the setup."

The large rookie class could provide more than a third of the starting lineup May 25, and maybe even the first rookie winner since Helio Castroneves in 2001.

"There's a couple of rookies with a lot of experience, so it's a definitely a possibility — for me," Power said.

Enrique Bernoldi, who finished the first three phases of the rookie test, and Mario Moraes, who made his first track appearance in the final minutes and did not get up to speed, were the only ones who did not complete all four phases of the test Sunday. They'll have another chance Monday, before full practice begins for rookies and veterans Tuesday.

"It's always a challenge," said Servia, recalling his first rookie try at Indianapolis in 2002, when he couldn't get enough speed in three qualifying attempts. "I'm just getting used to the car, and I wanted to get some miles and get some data to the guys and make the car faster, and I think we did that."

Alex Lloyd, who was fourth-fastest Sunday at 219.964 mph, Jay Howard and Jaime Camara moved up to the IndyCar Series from the developmental Indy Lights program. Hideki Mutoh, the Indy Lights series runner-up last year, made his IndyCar debut late last season at Chicago and joined Andretti Green Racing after Dario Franchitti left for NASCAR.

Lloyd is also a former winner at Indy, but on both the oval and road courses in Indy Lights, not the 500.

"Obviously, the speed is the biggest difference, but once you get a few laps in and get used to it, everything seems to slow down for you, and things felt very comfortable," Lloyd said.

"That's the nice thing about ROP," he said of the rookie program. "It kind of forces you to take your time and find your way up to speed safely."

Other rookies include Graham Rahal, the 19-year-old son of car owner and former Indy winner Bobby Rahal. The younger Rahal drove in 14 Champ Car races last season and won his IRL debut this year at St. Petersburg, Fla. He was eighth-fastest Sunday at 218.619 mph, right behind Camara's 219.175.

Howard, the 2006 Indy Lights champion, had 61 laps Sunday, with a top speed of 217.247 mph.

"We've got a full month, so there's no rush for us," Howard said. "We had a couple of issues just to start off. We got them ironed out and did our steps and went through them as we needed and got them out of the way."

The Champ Car points at Long Beach count in the IndyCar standings, so Power's win there puts him sixth — best among all rookies — behind veterans Castroneves, Scott Dixon, Dan Wheldon, Tony Kanaan and Danica Patrick.

"There are a lot of new competitors, very deep competition," said Speedway boss and Indy Racing League founder Tony George, whose open-wheel merger with Champ Car brought a flock of teams and drivers into the IndyCar Series this season. "It's not going to be a layup to get into this race, that's for sure."