HAMPTON, Ga. -- Dale Earnhardt Jr. likened Monday's test session with Hendrick Motorsports to attending a new school.

New faces, new names and a new way of doing things.

Earnhardt drove for Hendrick, his new team starting next season, at NASCAR's Car of Tomorrow test at Atlanta Motor Speedway. Earnhardt will finish the season with Dale Earnhardt Inc., but the switch allowed him to start work with his new team for at least two days.

Nearly every Nextel Cup team took part except title contenders Jeff Gordon and Jimmie Johnson.

Car owner Rick Hendrick admitted Sunday that having Earnhardt in one of his cars for this test was "a day we've been waiting for."

Earnhardt wasn't alone with new surroundings. Kyle Busch drove for Joe Gibbs Racing, Scott Riggs drove for Haas-CNC Racing and Travis Kvapil drove for Yates Racing, among those working with the new teams for the two-day session.

The test is meant to help teams run the Car of Tomorrow next season on the 1.5- and 2-mile tracks.

The cars ran only on short tracks, ovals less than 1.5 miles, road courses and one Talladega race this season in the debut.

The test also eased Earnhardt's adjustment to his new surroundings with Hendrick. It helped that his crew chief at Dale Earnhardt Inc., Tony Eury Jr., joined Hendrick earlier this month. This test reunited them.

Most everything else was new, though, including a carbon fiber seat in one of the two cars Earnhardt drove Monday.

"The adjustment period, I think the hard part for me is ... it's like going to a new school, making new friends," Earnhardt said. "It's hard to make friends. It's hard to build relationships. I had such a great rapport and great relationship with all the guys on my team I'm currently with, and to have to go through the challenge of that and building that respect and trust with a whole new group's going to be tough."

Earnhardt admitted it was different to see the No. 8 car with another driver.

"It's a unique situation to see it down in the garage," he said. "I'm sure the car is going to be a rocket ship. It was [Sunday]."

Earnhardt was headed for a top-three finish when his left rear wheel fell off and he crashed. He said the left wheel had been coming loose all race and that he even had a couple of competitors drive alongside the car to check it before that caution.

Earnhardt, who said he was sore from the incident, admits he should have pitted.

"I was frustrated," he said. "We hadn't got our finishes this year. Thought we could steal a third place there, cost me a good spot, good finish. I was just disappointed that I didn't do a better job, not only my own safety, but everybody else."

NASCAR gas

At least two teams discovered water in their fuel system that caused problems in Sunday's race. Dave Blaney and Denny Hamlin both had that issue.

The water in the fuel was blamed by Hamlin's team for failing to accelerate while leading on the next-to-last restart.

Martin Truex Jr. couldn't get out of the way and rammed Hamlin's slower car. Hamlin's crew chief, Mike Ford, said that Hamlin had more than two gallons of fuel in his car. Ford also said the team saw evidence of water in the fuel after a pit stop early in the race.

John Darby, Nextel Cup series director, said series officials are investigating. He said officials found a small amount of water in the fuel system of Jimmie Johnson's winning car in a post-race inspection.

Darby could not say how many teams had water in the fuel system but said it was enough to rule out sabotage.

Series officials and Sunoco officials are checking to see where the water came from.

Underground tanks were tested each day and did not show signs of water, leading Darby to suspect a bad pump.

Darby said the amount of water found in some filters in cars was about a teaspoon.

He said more than that was found in the cars of Blaney and Hamlin.

Martinsville schedule the same

Martinsville Speedway announced that its 2008 NASCAR Sprint Cup Series will be the same as this season.

The Goody's Cool Orange 500 will be Sunday, March 30, 2008, and the Subway 500 -- the sixth race of the Chase -- will be Sunday, Oct. 19.

The Craftsman Truck Series races -- the spring Kroger 250 and fall Kroger 200 -- will be on the Saturdays before the Cup races.