Fontana IndyCar: Ryan Briscoe leads practice for Penske

Penske driver Briscoe took the honours half an hour into the 90-minute session with a 217.517mph lap that put him 0.083mph clear of owner/driver Ed Carpenter, who had been the benchmark during the first 30 minutes.

Carpenter's time was still good enough for him to remain second-quickest, with Ganassi's Dario Franchitti and the Penske cars of points leader Will Power and Helio Castroneves rounding out the top five.

Power's championship rival Ryan Hunter-Reay ended the morning with the 16th-fastest lap for Andretti Autosport.

The session was interrupted three times by yellow flags, two for debris and a third caused by Justin Wilson getting out of shape and crashing at the exit of Turn 2.

"I was on new tyres," Wilson said. "I was starting my second lap. I'm not sure why it didn't stick.

"It's disappointing; it set our whole weekend back. We'll just have to work on trying to get the car ready for tomorrow now."

The session was the only opportunity for teams to fine-tune their set-ups ahead of qualifying on Saturday afternoon.

Click here for AUTOSPORT's analysis of the IndyCar title showdown

Pos  Driver               Team/Car                    Time      Gap
 1.  Ryan Briscoe         Penske Dallara-Chevy        33.1008s
 2.  Ed Carpenter         Carpenter Dallara-Chevy     33.1842s  + 0.0834s
 3.  Dario Franchitti     Ganassi Dallara-Honda       33.2495s  + 0.1487s
 4.  Will Power           Penske Dallara-Chevy        33.2651s  + 0.1643s
 5.  Helio Castroneves    Penske Dallara-Chevy        33.2787s  + 0.1779s
 6.  Scott Dixon          Ganassi Dallara-Honda       33.3008s  + 0.2000s
 7.  Tony Kanaan          KV Dallara-Chevy            33.3484s  + 0.2476s
 8.  Marco Andretti       Andretti Dallara-Chevy      33.4625s  + 0.3617s
 9.  JR Hildebrand        Panther Dallara-Chevy       33.5291s  + 0.4283s
10.  Graham Rahal         Ganassi Dallara-Honda       33.8624s  + 0.7616s
11.  Katherine Legge      Dragon Dallara-Chevy        33.8930s  + 0.7922s
12.  James Hinchcliffe    Andretti Dallara-Chevy      33.9226s  + 0.8218s
13.  Justin Wilson        Coyne Dallara-Honda         33.9854s  + 0.8846s
14.  Rubens Barrichello   KV Dallara-Chevy            33.9949s  + 0.8941s
15.  Charlie Kimball      Ganassi Dallara-Honda       34.0648s  + 0.9640s
16.  Ryan Hunter-Reay     Andretti Dallara-Chevy      34.0790s  + 0.9782s
17.  Takuma Sato          Rahal Dallara-Honda         34.1331s  + 1.0323s
18.  Simon Pagenaud       Schmidt Dallara-Honda       34.2560s  + 1.1552s
19.  EJ Viso              KV Dallara-Chevy            34.2830s  + 1.1822s
20.  Sebastian Saavedra   AFS/Andretti Dallara-Chevy  34.3579s  + 1.2571s
21.  Oriol Servia         Panther/DRR Dallara-Chevy   34.3587s  + 1.2579s
22.  James Jakes          Coyne Dallara-Honda         34.4343s  + 1.3335s
23.  Wade Cunningham      Foyt Dallara-Honda          34.5841s  + 1.4833s
24.  Josef Newgarden      Fisher Dallara-Chevy        34.9272s  + 1.8264s
25.  Alex Tagliani        Herta Dallara-Honda         35.2897s  + 2.1889s
26.  Simona de Silvestro  HVM Dallara-Lotus           36.7714s  + 3.6706s