Andretti Autosport returned to the fray on Fast Friday after putting their feet up on Thursday, and soon dominated proceedings as they once again showed just how good they were working in traffic and getting a tow from other cars on track at the Indianapolis Motor Speedway.

On the final day of practice for the 96th running of the Indy 500 ahead of Saturday's qualifying session, Marco Andretti went to the top of the timesheets for the second time this week with a mighty lap of 227.540mph (39.5535s), partly thanks to the extra 40-50 horsepower turboboost allowed by the IZOD IndyCar Series organisers today and for the qualifying weekend.

"Today was a big day for us," said Marco. "We kind of woke the car up and obviously with this added boost today it woke my car up, in particular, as well.

"It would be cool to be able to be on the pole tomorrow, for sure. Hopefully, tomorrow if we're knocking on the door for a pole, that'd be pretty ironic because last year we were just trying to get into the show."

Asked what had made the difference in the intervening 12 months, Andretti pointed to the team work in the garage. "It's just credit to the guys. We've just been working so hard, and I think that Al McDonald, my engineer, and I have been working really well together. He has a lot of faith in me and vice-versa, so that's all you need is that kind of chemistry."

Last year's pole position time for the centennial Indy 500 was set by Alex Tagliani with a speed of 227.472mph in a Sam Schmidt Motorsport car engineered by McDonald.

Andretti's time on Friday was 0.1229s ahead of second-placed man Ryan Briscoe (226.835mph, 39.6764s), who was just faster than his Penske team mate Helio Castroneves in third (226.716mph, 39.6973s).

"I think everyone up there had a tow - I had a lot of help on the last lap from Bourdais," admitted Briscoe. "I think we're up there, definitely top nine, for sure. It's hard to know where everybody stacks up because it's hard to get a clean lap, but we're up there. We're competitive, and we're certainly going to work hard tonight."

"I felt we made a lot if improvements," agreed Castroneves. "Today certainly helped prepare us for tomorrow, and I'm really looking forward to qualifying."

After having successfully completed their program of practice testing and developing early, Andretti Autosport's five-car squad has essentially sat out Thursday on the sidelines, but roared back into life with an impressive dominating performance on Fast Friday that saw them take four of the top ten spots.

As well as Andretti on the lead spot, Ryan Hunter-Reay was in third with a lap speed of 227.540mph (39.5535s), James Hinchcliffe was sixth place (225.974mph, 39.8276s) and Ana Beatriz an impressive seventh (225.653mph, 39.8842s).

"All of the credit for our speed goes to the entire Andretti Autosport team," said Hunter-Reay. "Everybody's been digging really deep to get everything out of the cars, and that says a lot about this team. We're all working together on and off the track, and that makes a huge difference."

"From where we're sitting, we're very happy," agreed Hinchcliffe. "We've made a couple of gains throughout the day, and we're just going to polish the GoDaddy car, put it away and really focus on tomorrow."

"I think the Andretti team did an awesome job and now the cars are pretty fast, so I am proud today," said Beatriz. "If we want to make sure we are in the top ten I think we still need to work a little bit, and hopefully tomorrow we'll get some more speed and get a little closer to our teammates."

Of the Andretti line-up, only Sebastian Saavedra missed out on the top ten finishing back in 19th position with a lap of 224.661mph (40.0604s), while the missing Penske man was championship leader Will Power who was just outside the top ten in 11th with a lap of 225.288mph (39.9488s).

"We accomplished a fair bit with our Verizon car today," said Power. "We would've liked to find just a touch more speed, although we always want that. Looking ahead to tomorrow: We're in good shape, really, and we will give it a go."

With Andretti and Penske proving so strong, the only Honda representation in the top ten was from the Ganassi duo of Scott Dixon in fifth (226.224mph, 39.7836s) and Dario Franchitti in ninth (225.370mph, 39.9344s).

"We're definitely not where we need to be," admitted Dixon. "I sort of got a big tow lap there at the end that sort of pulled us up the chart, but realistically I think we're around ninth. We're not where we want to be."

"Scott and I are the first two of the Honda-powered cars right now, and I think we have some work to do," agreed Franchitti. "That's it, really. It can't be roses every day, and you just need to keep pushing."

Worryingly for the Honda camp, two of their line-up of cars were sidelined during the day. Michel Jourdain Jr.'s Rahal Letterman Lanigan car suffered an engine problem just 55 minutes into the session, crawling to a halt on the backstretch with smoke and flames visible.

"Not such a good day," admitted Jourdain. "Unfortunately we had a problem early on and we didn't run many laps ... I felt a loss of power, and the guys told me to shut it down. I don't know what they saw in the telemetry, but they told me to shut it down. Then I saw smoke, so there was a fire.

"It was our first run, and we were just starting to trim the car," he added. "I could definitely feel the difference in power with more boost. It was fun to drive."

Panther/Dreyer & Reinbold's Oriol Servia feared the same thing had happened to him early in the session, only to find that the problem wasn't solved by replacing the engine after all.

"Obviously, it was not in our plan nor was it our ideal day because we wanted to get a feel of the car," said Servia. "We started the car, and we saw some smoke and thought it was the engine. We rushed to change it to try to get out on track. When we put in the new engine, it was still smoking just as much, which we then discovered that it didn't have anything to do with the motor."

The remainder of the top ten consisted of 2011 Indy 500 runner-up JR Hildebrand who was eighth in the Panther Racing car with a lap of 225.571mph (39.8987s) and KV Racing Technology's Tony Kanaan in tenth (225.322mph, 39.9428s).

"We feel pretty good - we'd like to find a little more speed in the National Guard Chevy, but we more or less accomplished everything we set out to do today," said Hildebrand. "Now it's just a matter of trying to figure out what our target speed will end up being when Pole Day comes around tomorrow."

The two Lotus drivers, Jean Alesi (Fan Force United) and Simona de Silvestro (HVM Racing) were once again significantly slower than any of the other cars out on the track on Friday. Both cars had received a 'sneak preview' of the turbo boost earlier in the week - which had helped Alesi achieve the speeds required to complete his Rookie Orientation Program - but even so were around 2mph better than their previous boosted best speeds of the week, showing definite progress.

"We have been getting better day after day, and doing what we have to do, and now the next thing we have to do is qualifying, as we prepare for the race," said Alesi, sounding happier than he had done mid-week. "The balance on the car is good ... I feel we have a good car under us, and I could notice the horsepower change we had in the engine."

"A pretty good day," agreed de Silvestro. "We made progress and found a little bit of speed. I think we should be all right for qualifying."

The Dragon Racing duo were also toward the back of the grid, but considering it was only the second day for the team with their new Chevy engines they were still showing impressive instant speed out of the box: Sebastien Bourdais put in a very presentable lap of 221.191mph (40.6888s) and Katherine Legge was close behind with a best time of 219.430mph (41.0154s).

"We're not even worried about qualifying," said Legge. "If we just get it in the field, we'll get ready for the race."

Legge was able to complete the final phase of her Rookie Orientation Program with no problems to make her eligible for Saturday's qualifying, while Bourdais was also able to satisfactorily run the final laps of his refresher program during Fast Friday.

"No major drama, no moments, no nothing. Just what we want as we build confidence and get data," said Bourdais. "We're just going through what we can with the little time we've got. We were able to get in quite a few laps and get a lot of done. We have to keep still working at it to try to get some more speed out of the car."

Schmidt-Hamilton's Simon Pagenaud got a "weird" call to report for duty half an hour before the official noon start of the six-hour qualifying session, and found himself being presented with a surprise cake to mark his 28th birthday. "It's really nice from the guys," he said. "It is really such a great atmosphere in this team."

The weather continued to be exceptionally perfect for the teams and drivers, registering in the 80s Fahrenheit all afternoon with blue skies and sunshine sending the track temperature up to 125 degrees. The wind was down to an easterly 8mph breeze on Friday, and conditions for the qualifying weekend look set to remain more of the same.

In total there were 32 drivers at work on Fast Friday running a combined total of 1206 laps. There were four cautions for a total of 36 minutes under yellow, one for Jourdain's engine failure and three for routine track inspections or debris clean-up.

Full practice 7 times available.