Will Power leads Penske 1-2 in second practice, Alonso 24th

Power's team-mate Helio Castroneves finished the day second quickest, with Gabby Chaves ending up third fastest in his Harding Racing Chevrolet.

McLaren Formula 1 driver Fernando Alonso was only 24th, but did complete over 100 laps.

During an incident-free afternoon, Power set his quickest lap on his 47th tour at 224.656mph, with the benefit of a tow.

However, 16mph gusts affected the cars and appeared to artificially keep the speeds down.

"The grip's pretty good, a lot of rubber has gone down," he said.

"The car's pretty good and I feel alright in traffic."

Power also set the fourth fastest lap that did not have the aid of a draft, although the Ed Carpenter Racing cars of Ed Carpenter and JR Hildebrand were first and third in the no-tow speed charts, and tenth and ninth overall.

Castroneves jumped up to second overall at 224.287mph with 45-minutes of the six-hour session remaining but was down in 17th place on the no-tow charts.

Chaves grabbed third in the final 10 minutes at 223.991mph - 19th overall - with Ryan Hunter-Reay the top Honda runner in fourth place at 223.960mph for Andretti Autosport.

His team-mate, two-time F1 world champion Alonso, racked up the most laps of any driver with 117, and sampled slipstreaming for the first time in his IndyCar oval career.

He usually spent his time drafting in an Andretti Autosport train, but was also spotted dicing with Power, AJ Foyt Racing's Carlos Munoz, and James Hinchcliffe of Schmidt Peterson Motorsports.

Alonso ended the day with a best speed of 221.029mph, and was a very healthy 14th without the aid of a tow - third fastest of the six Andretti Autosport drivers on that chart.

Also looking strong on the no-tow chart were the Chip Ganassi Racing cars, with Charlie Kimball second, Scott Dixon fifth and Tony Kanaan in 10th.

TUESDAY PRACTICE RESULTS: