Castroneves leads Friday practice

Penske driver Helio Castroneves recorded a lap of 1:13.3130 (101.646 mph) around the 2.125-mile, 14-turn street course, to beat Dario Franchitti's morning time by 0.0317 seconds.

"The track seemed to be changing quite a lot throughout the day," Castroneves said.

"At one point, we were improving our time, and then within the next few laps, the times were slower. You're like, 'What is going on?'

"But of course all this is typical with a concrete surface. As we put more rubber down, the track will get faster."

The drivers who were returning to the Detroit course, which was used for CART Champ Car races from 1992 to 2001, encountered the same bumpy streets and rapidly changing surface that they remembered.

Points leader Scott Dixon, who was a CART rookie during the 2001 Belle Isle race, spun during practice.

"It's been a bit of a struggle just trying to get the car back up to speed and make sure we get into the fast five this afternoon," he said.

"We've been moving along pretty consistently. I feel we made a few changes toward the end that put us in the right direction."

The Belle Isle event stands as a critical point in the championship race between Dixon and Franchitti.

"It's come down to the wire," said Dixon, who leads Franchitti by four points.

"Two races left, four points. One of us could have a problem this weekend, or one of us could have a problem next weekend (in the finale at Chicagoland Speedway). It's definitely going to come down to Chicago."

Franchitti lost the points lead he had held for much of the season by finishing third while Dixon won at Infineon Raceway last Sunday. Both drivers are aware that mistakes at this stage will be very costly.

"It's been that way for quite a while," Franchitti said. "It's no different now."

Afternoon practice times:

Pos  Driver             Team               Time
 1.  Helio Castroneves  Penske             1:13.3130
 2.  Dario Franchitti   Andretti-Green     1:13.4702  + 0.1572
 3.  Scott Dixon        Ganassi            1:13.7286  + 0.4156
 4.  Tony Kanaan        Andretti-Green     1:13.7434  + 0.4304
 5.  Marco Andretti     Andretti-Green     1:14.5218  + 1.2088
 6.  Ryan Hunter-Reay   Rahal-Letterman    1:14.6862  + 1.3732
 7.  Vitor Meira        Panther            1:14.6865  + 1.3735
 8.  Sam Hornish Jr     Penske             1:14.8298  + 1.5168
 9.  Tomas Scheckter    Vision             1:15.0778  + 1.7648
10.  Darren Manning     Foyt               1:15.3621  + 2.0491
11.  Danica Patrick     Andretti-Green     1:15.7939  + 2.4809
12.  Scott Sharp        Rahal-Letterman    1:15.8556  + 2.5426
13.  Kosuke Matsuura    Panther            1:16.5951  + 3.2821
14.  Dan Wheldon        Ganassi            1:16.7193  + 3.4063
15.  Ed Carpenter       Vision             1:16.8512  + 3.5382
16.  Buddy Rice         Dreyer & Reinbold  1:17.2411  + 3.9281
17.  Sarah Fisher       Dreyer & Reinbold  1:17.8633  + 4.5503