Team Penske's Will Power ended up setting the best time of the two-day open test session at Barber Motorsports Park, and was alone in posting a speed in excess of 123mph on the 2.38-mile, 17-turn permanent road course.
The reigning IndyCar Series champion recorded a best laptime of 123.01mph (1:07.3118s) in the morning session, significantly faster than his own 2014 pole-winning qualifying lap of 1:08.3120s on the Firestone red walled alternate tyres.
Full Barber open test times from day 2
The pre-season test was the first opportunity for all teams and drivers to run the new street/road course aero kit bodywork provided by engine manufacturers Honda and Chevrolet that will be used for the 2015 season. On the basis of this week's test, it's the Chevrolet-backed teams that hold the early advantage with the top six drivers all aligned with the bow tie brigade, and only two drivers in the top ten from the Honda stable.
"The aero kits produce so much more downforce and there's a lot of grip, so the cars are faster everywhere,” Power explained. "I would expect to break lap records just about everywhere. I think we found some good stuff as a team for St. Petersburg and when we come back to race here [at Barber in April.]"
While Power and and his Penske team mates Helio Castroneves, Simon Pagenaud and Juan Pablo Montoya came out with a significant edge over their rival teams - all four drivers ending the test in the top ten - the runners-up honours on the timesheets when to Power's Ganassi rival Scott Dixon, who posted an impressive lap of 122.849mph (1:07.3996s) to top the final four-hour session on Tuesday afternoon.
More of a surprise was the eye-catching effort of KV Racing Technology's new signing from the GP2 Series, Stefano Coletti, who finished second to Power in the morning and with the third fastest time of the overall test with a time of 122.626mph (1:07.5224s)
"For me, the first time here and I really like this track," said Coletti, who ended the session six hundreds of a second faster than his experienced team mate Sebastien Bourdais. "It's a lot of fun to drive, demanding and physical. We've been working on getting the proper baseline set-up so I could feel good in the car and started pushing today.
"There is a lot of difference between the old car and the new one," he noted, comparing the performance he'd experienced in a prior test using the old standardised Dallara aerodynamic parts. "Obviously, there is a lot more downforce and it's a lot quicker."
Castroneves was fourth fastest overall courtesy of his time on Tuesday afternoon, while his team mate Pagenaud was sixth fastest overall thanks to his best lap on Monday. The fastest Honda driver was Graham Rahal in the #15 Rahal Letterman Lanigan Racing, a little over three tenths off Power's target time.
Overall, the drivers were very positive with the date collected on the new aero kits this week. "As far as overall driving style we've been pretty pleased that the kit hasn't greatly upset a lot of the base knowledge that we have of the car,” said Schmidt Peterson Motorsports' new signing James Hinchcliffe, who was 12th fastest overall.
"You can be a bit braver in certain corners, but I don't think I've had to revamp what I've been doing, which is nice," he added. "It's not like when we went from the IR-03 to the DW12; that was a complete change in driving philosophy for me. This has been a nice progression of more grip, more downforce, more fun.
“There is still some bit to come and a lot of development to do.," Hinchcliffe admitted. "This car is going to get better and better through the first half of the year as we understand more and more. To see the times we've been doing given the warm track conditions, it gives you a lot of confidence heading into St Pete to see records fall."
In all, 21 of the 23 participating drivers finished the two days within one second of Power's benchmark. The two drivers to miss out on that achievement were both rookies, Sage Karam and Francesco Dracone.
Ganassi's Karam only ran three laps throughout the entire test, because of a high speed crash early on Monday morning that inflicted serious damage on the safety cell of the #8. Karam also hurt his wrist and arm in the impact, and while initial reports said that he had done so serious harm he nonetheless spent Tuesday back in Indianapolis for further evaluation by IndyCar's medical consultant Dr Terry Trammel.
It was also a difficult test for Dracone, newly confirmed at Dale Coyne Racing for the first four races of the 2015 season at St Petersburg, New Orleans, Long Beach and Barber. The 31-year-old Italian was understandably significantly slower on his first day in the car on Monday, and then wasn't able to get out on track at all on Tuesday morning. He was back out on track in the afternoon for a further 46 laps, but still ended the test over four seconds off Power's pace with a best time of 1:11.6317s (115.591mph).
"The test was a challenge for the team and for me," Dracone conceded. "The settings of the car were something the team hasn't had to deal with before but we made the best of what we had.
"We had the new floor and the old aero kit on the car so we had very low downforce," he continued. "It was good to get some laps in and learn the circuit and get to know the team and the engineers. Other than that there isn't a lot to take away from the test."
Teams will now continue to work with the new aero kits in private tests over the next week and a half, before reconvening March 27 for the opening of practice on the 1.8-mile, 14-turn temporary St Petersburg, Florida street circuit that hosts the 2015 season opener on March 29.
Full Barber open test times from day 2