Marco Werner drove the ADT Champion Racing Audi R8 to the fast time of the day Friday as American Le Mans Series teams had their first day of testing for Sunday's Infineon Grand Prix of Sonoma at Infineon Raceway.

NASCAR star Dale Earnhardt, Jr., driving in the race with the factory Chevrolet Corvette team in the GTS class, got his first laps ever on the full 2.53-mile Infineon Raceway circuit and steadily improved his times during the two-hour session. Co-driver Boris Said recorded the third-fastest time in class during the session.

Werner and co-driver JJ Lehto are seeking their third straight win in the American Le Mans Series in Sunday's two-hour, 45-minute timed event. Werner turned a lap of 1:23.397 to lead the 26 cars that participated in Friday's test session. Official practice and qualifying will be held Saturday.

Second-fastest in the session and in the LMP1 class was the Dyson Racing Lola EX257-AER/MG of James Weaver and Butch Leitzinger, overall winner of last year's race, at 1:23.915. The other Dyson entry of Chris Dyson and Andy Wallace was third at 1:24.147.

"We did some tire testing with the car today and they are working very well," said Werner, last year's Prototype champion in the ALMS. "I think we are prepared for the practice tomorrow and for the race on Sunday. Being in front of the Dyson cars today is a very good start for us."

Corvettes were 1-2-3 in the GTS class, with Oliver Gavin setting the fastest class time at 1:29.704 in the #4 car he will share with Olivier Beretta. Ron Fellows and Johnny O'Connell, seeking their record fourth straight win at Infineon, were second at 1:30.257, followed by Said and Earnhardt at 1:30.593. Earnhardt's best lap was 1:31.8.

"In my opinion, it might be one of the greatest cars I've ever driven," said Earnhardt of the Chevrolet Corvette C5-R. "It's really easy to get in there and be a quick learner. I've been in the car before and I've been around the people before, so all those things make it easier to adjust. I was really glad to be able to get out there today and be competitive, and give Boris and these guys some confidence. We went and tested at GingerMan (Michigan) and that was a big help."

Robin Liddell, driving the Intersport Racing Lola B2K/40-Judd, led the way in the LMP2 class for smaller, less-powerful Prototypes with a time of 1:30.782. He will co-drive with Clint Field as the two seek their second win together this season.

"I'm knackered!" said Liddell. "I flew all day from England, got to my hotel at 3 a.m. and I've been up for 27 hours. The track's been repaved and all of my skid marks from last year have been erased. I'm hoping not to put down any new ones this year. I'm looking for a 100 percent winning record with Clint."

Second-fastest in the LMP2 class was the Team Bucknum Racing Pilbeam MP91 of Jeff Bucknum, Bryan Willman and Chris McMurry at 1:31.314, while third was the Miracle Motorsports Lola-Nissan of James Gue and Ian James at 1:33.849.

The GT class was very close, led by the Alex Job Racing Porsche 911 GT3 RSR of Romain Dumas and Marc Lieb at 1:35.178. The other Job Porsche of Jorg Bergmeister and Timo Bernhard was second at 1:35.472, followed by the J3 Racing Porsche of Tim Sugden and Justin Jackson at 1:35.621.

Sunday's race starts at 11 a.m. (PDT) and will be televised in North America by CBS Sports from 3-5 p.m. (EDT). MotorsTV will have live coverage in Europe. The American Le Mans Series Radio Web will have live coverage online at americanlemans.com.

Friday's testing times:

1. JJ Lehto and Marco Werner, Audi R8 (LMP1), 1:23.397.

2. James Weaver and Butch Leitzinger, Lola EX257-AER/MG (LMP1), 1:23.915.

3. Chris Dyson and Andy Wallace, Lola EX257-AER/MG (LMP1), 1:24.147.

4. Jon Field and Michael Durand, Lola B160-Judd (LMP1), 1:27.816.

5. Oliver Gavin and Olivier Beretta, Chevrolet Corvette C5-R (GTS), 1:29.704.

6. Ron Fellows and Johnny O'Connell, Chevrolet Corvette C5-R (GTS), 1:30.257.

7. Dale Earnhardt, Jr., and Boris Said, Chevrolet Corvette C5-R (GTS), 1:30.593.

8. Clint Field and Robin Liddell, Lola B2K/40-Judd (LMP2), 1:30.782.

9. Jeff Bucknum, Chris McMurry and Bryan Willman, Pilbeam MP91 (LMP2), 1:31.314.

10. David Brabham and Peter Kox, Lamborghini Murcielago R-GT (GTS), 1:33.608.

11. Ian James and James Gue, Lola B2K/40-Nissan (LMP2), 1:33.849.

12. Romain Dumas and Marc Lieb, Porsche 911 GT3 RSR (GT), 1:35.178.

13. Timo Bernhard and Jorg Bergmeister, Porsche 911 GT3 RSR (GT), 1:35.472.

14. Tim Sugden and Justin Jackson, Porsche 911 GT3 RSR (GT), 1:35.621.

15. Leo Hindery and Lucas Luhr, Porsche 911 GT3 RSR (GT), 1:35.709.

16. Tom Weickardt and Jean-Phillipe Belloc, Dodge Viper GTS-R (GTS), 1:35.831.

17. Ralf Kelleners and Anthony Lazzaro, Ferrari 360 Modena (GT), 1:36.005.

18. Johannes van Overbeek and Darren Law, Porsche 911 GT3 RSR (GT), 1:36.367.

19. Cort Wagner and Patrick Long, Porsche 911 GT3 RSR (GT), 1:36.598.

20. Lonnie Pechnik and Seth Neiman, Porsche 911 GT3 RSR (GT), 1:36.828.

21. David Murry and Craig Stanton, Porsche 911 GT3 RSR (GT), 1:36.920.

22. Peter Boss and Hugh Plumb, Porsche 911 GT3 RS (GT), 1:37.910.

23. Terry Borcheller and Johnny Mowlem, Saleen S7R (GTS), 1:37.923.

24. Pierre Ehret and Jim Matthews, Porsche 911 GT3 RSR (GT), 1:38.345.

25. Gunnar Jeannette and David Saelens, Panoz Esperante GT-LM (GT), 1:38.652.

26. Tracy Krohn and Dave McEntee, Lamborghini Murcielago R-GT (GTS), 1:44.241.