CONCORD, N.C. (AP) — Jimmie Johnson has three championships under his belt and is full steam ahead in pursuit of a fourth.

Seven, though? He doesn't think he's got that in him.

The three-time defending champion said Wednesday he believes the NASCAR record of seven titles will probably never be broken. The mark is shared by Richard Petty and the late Dale Earnhardt.

Johnson's teammate, Jeff Gordon, leads all active drivers with four championships — a mark Johnson is trying to equal this season.

"Man, seven, I don't think it's possible," Johnson said at Lowe's Motor Speedway, where he was seated next to Petty after a small ceremony declaring the two drivers "Kings of the Sport."

"With what Richard did and what Earnhardt Sr. did, I just don't think seven is a number you are going to get to. It's tough. You look at Jeff, trying to get his fifth, and all the success he's had, I think they're safe up there with seven. I hope to prove them wrong, I'm not saying I don't want to try, but we're at three."

Johnson is currently ranked second in the standings and trails Hendrick Motorsports teammate Mark Martin by just 10 points.

But he's coming off a dominating win Sunday at Dover International Speedway, where he completed a season sweep that left the rest of the championship challengers frustrated by another Johnson victory.

"There's Jimmie and then there's Jimmie and Jimmie," LMS owner Bruton Smith said, motioning to Johnson. "What are you going to do with a guy who makes everybody look bad? Jimmie made everybody look bad last week."

Although many fans are turned off by Johnson's dominance the past three seasons, Smith refused to blame the champion for NASCAR's struggles this year in ratings and attendance.

"He's a wonderful person," the billionaire said. "He qualifies as Mr. America, as far as I'm concerned. I'm just glad he's in this sport and not some sport we don't care so much about."

Despite all the praise, Smith agrees that Johnson won't likely reach seven titles.

"Richard was in an era, I saw him many times when he unloaded, he was already a second faster than everybody else," Smith said. "As hard as it is to win one of these races today, I just don't think it will happen. Jimmie, if he's still racing when he's 55 or something, he might stand a chance. But it will take a long-term effort."

Petty, who also has a record 200 victories, also thinks Johnson will have a hard time catching him.

"He could win seven in a row, anything is possible, and there's no record that's ever been set that can't be broken," Petty said. "But like Jimmie said, it's not likely."