Polesitter Helio Castroneves underlined his status as the man to beat in the Indianapolis 500 by topping the traditional Carb Day practice session – the final chance for teams to fine-tune their setups prior to Sunday's race.

The Penske driver set his time of 40.1929 seconds on only his third lap and then remained unbeaten for the rest of the hour.

His teammate Will Power completed a Penske one-two as he prepared for what could be his last IndyCar Series race of the year, with Ryan Briscoe emphasizing Penske's pace in fifth place.

Mario Moraes impressed again in third place, and with his teammates Townsend Bell and Paul Tracy taking ninth and 12th, KV Racing Technology looks in extremely good shape going into its second Indy 500.

Dan Wheldon suggested he will rapidly move forward from his 18th place on the grid by going fourth quickest for Panther Racing today, with Ganassi duo Dario Franchitti and Scott Dixon, and fourth-place qualifier Graham Rahal (Newman/Haas/Lanigan) completing the top eight.

Davey Hamilton set a promising 10th-fastest time in the best of Dreyer & Reinbold's four entries - but it was an underwhelming session for race's only other four-car squad, Andretti Green Racing, as its top runner Tony Kanaan was back in 11th.

RESULTS:
Pos  Driver             Team                     Time      Gap
 1.  Helio Castroneves  Penske                   40.1929s
 2.  Will Power         Penske                   40.2577s  + 0.0648s
 3.  Mario Moraes       KV                       40.3676s  + 0.1747s
 4.  Dan Wheldon        Panther                  40.4701s  + 0.2772s
 5.  Ryan Briscoe       Penske                   40.4724s  + 0.2795s
 6.  Dario Franchitti   Ganassi                  40.4754s  + 0.2825s
 7.  Scott Dixon        Ganassi                  40.5374s  + 0.3445s
 8.  Graham Rahal       Newman/Haas/Lanigan      40.5824s  + 0.3895s
 9.  Townsend Bell      KV                       40.6441s  + 0.4512s
10.  Davey Hamilton     Dreyer & Reinbold        40.6557s  + 0.4628s
11.  Tony Kanaan        Andretti Green           40.7049s  + 0.5120s
12.  Paul Tracy         KV                       40.7278s  + 0.5349s
13.  Vitor Meira        Foyt                     40.7966s  + 0.6037s
14.  Raphael Matos      Luczo Dragon             40.8445s  + 0.6516s
15.  Marco Andretti     Andretti Green           40.8710s  + 0.6781s
16.  AJ Foyt IV         Foyt                     40.8870s  + 0.6941s
17.  Scott Sharp        Panther                  40.9133s  + 0.7204s
18.  Tomas Scheckter    Coyne                    40.9302s  + 0.7373s
19.  Alex Tagliani      Conquest                 40.9401s  + 0.7472s
20.  Hideki Mutoh       Andretti Green           40.9786s  + 0.7857s
21.  Ed Carpenter       Vision                   40.9833s  + 0.7904s
22.  Mike Conway        Dreyer & Reinbold        40.9910s  + 0.7981s
23.  Danica Patrick     Andretti Green           41.0344s  + 0.8415s
24.  Oriol Servia       Rahal Letterman          41.0364s  + 0.8435s
25.  Alex Lloyd         Schmidt/Ganassi          41.0467s  + 0.8538s
26.  Justin Wilson      Coyne                    41.1111s  + 0.9182s
27.  Ryan Hunter-Reay   Vision                   41.1725s  + 0.9796s
28.  Robert Doornbos    Newman/Haas/Lanigan      41.2534s  + 1.0605s
29.  EJ Viso            HVM                      41.3246s  + 1.1317s
30.  Milka Duno         Dreyer & Reinbold        41.3604s  + 1.1675s
31.  Sarah Fisher       Fisher                   41.4145s  + 1.2216s
32.  John Andretti      Dreyer & Reinbold/Petty  41.4181s  + 1.2252s
33.  Nelson Philippe    HVM                      41.5453s  + 1.3524s