HAMPTON, Ga. — Dale Earnhardt Jr. zipped up the white racing suit, this one with a shoe company’s name plastered across his chest instead of a popular beer, and climbed into a car that made him look even more out of place.

It was white instead of red. No. 5 was painted on the side instead of No. 8. The logo was for Hendrick Motorsports, not the team that bears the name of his late father.

Earnhardt gave an intriguing glimpse of what the very near future holds on Monday, taking the wheel of a new car with his new team for the first round of a two-day testing session at Atlanta Motor Speedway.

Junior was tired from NASCAR’s grueling schedule and sore from a nasty crash the previous day, when a hard lick in the closing laps cost him a chance to go for the win in a Nextel Cup race on this same 1.5-mile oval.

Still, Earnhardt got down to work with Hendrick Motorsports, which will be his home beginning in 2008 following a nasty split from Dale Earnhardt Inc. and its owner, stepmother Teresa Earnhardt, who remains his boss for three more races.

“It’s like going to a new school and trying to make new friends,” Earnhardt said. “It’s hard to make friends. It’s hard to make relationships when you’re starting over with a new group of guys. I have a great rapport with all the guys on the team I’m currently with. I’m going through the challenge of building respect and trust with a whole new group of guys.”

At least he heard a familiar voice over the radio. Tony Eury Jr., his cousin and one-time crew chief at DEI, has already made the move to Hendrick, getting a head start on next season.

“It’s really cool to be back with him,” Eury said. “I’m trying to be the bridge between Hendrick Motorsports and Dale Jr. so they can understand him quicker. We’ve got a lot of work to do to make sure it’s game on when February comes.”

Since announcing his move to Hendrick, Earnhardt has walked a balancing act between his new team and soon-to-be-former operation. He conceded that it was a little strange to head to a different hauler on Monday, leaving Regan Smith to drive Junior’s No. 8 in testing.

“A couple of guys from the 8 car came over to see me today and asked me if I was all right and how things were going with the 5 car,” Earnhardt said. “They’re looking out for me. We have work left to do there, and we’re going to do it.”

Earnhardt had endured a difficult season, on and off the track. A series of blown engines scuttled his chances of qualifying for NASCAR’s 10-race playoff, leaving him as both a lame duck and a guy who has no chance of winning the Nextel Cup.

But he’ll be moving to the powerful Hendrick team, which already has the top two contenders in the title race, Jeff Gordon and Jimmie Johnson. Casey Mears will actually take over Kyle Busch’s No. 5 car, while Earnhardt switched to No. 88 so he can retain some link to his past. Negotiations to bring the single 8 with him from DEI fell through.

This wasn’t Earnhardt’s debut behind the wheel of a Hendrick machine. That came in April, when he jumped into Busch’s No. 5 car at Texas after a crash that took out both drivers.

But this was Junior’s official debut with his new team, an occasion that Hendrick marked by having him drive a specially painted car bearing the company’s original name, All-Star Racing, its former white and red paint scheme and a throwback sponsor, “City Chevrolet.”

Earnhardt also broke out his new white racing suit, which had Adidas in red letters across the front instead of the more familiar Budweiser, which has been his sponsor since he broke into the sport and quickly became one of its most followed drivers.

“I don’t know what it’s supposed to feel like yet,” he said. “This is just getting an opportunity to work with these guys a little early. I’m still focused and dedicated toward finishing my job with dignity over at the 8 car. That’s important to me.”

Busch signed on with Joe Gibbs Racing. He tested Monday in the No. 18, which will be his car next season, and couldn’t resist a jab at the guy who was driving the 5.

“It felt good to actually pass it,” Busch said, breaking into a smile. “I’m going to miss the guys. I’ve been working with them for three years. But sometimes you’ve got to move on to bigger, better, badder things elsewhere.”

Busch looked good with his new team. He put up the fastest speed of the morning session (186.190 mph) and was third-fastest in the afternoon (184.358).

Earnhardt drove two versions of the 5 car, running seventh-best in the morning (184.450) and eighth in the afternoon (183.667).

Clearly, he would have preferred to take a few days off instead.

“I was looking forward to it waking up this morning, but I knew by lunchtime that the actual testing part of it was going to be boring as always,” Earnhardt said. “We’ve been here all weekend. I think NASCAR is trying to punish us for some reason. I know it’s a lot more convenient to just stay here, but, man, it makes for a long week.”

Earnhardt plans to remain the same blue jeans-wearing, shirttail-hanging-out sort of guy he’s always been, but Eury has already made some concessions to joining the more buttoned-down operation at Hendrick.

“I’m wearing my shirttail in and I got my hair cut,” the crew chief said. “Dressing up is fine. It’s part of the deal, and it’s good to look nice.”