LAS VEGAS --- Kyle Busch and Tony Stewart are known for their racing success and explosive tempers.
Most every problem on the track is followed by a profanity-laced rant and a tantrum. It was boorish behavior, but tolerated. Nothing was going to change NASCAR's two biggest bad boys.
Until, that is, they changed.
Busch and Stewart seem to have mellowed this season. That was never more apparent than Sunday at Las Vegas Motor Speedway. Both had a chance to win, and neither did.
Busch was done in first by a flat tire, then a blown engine. He was running second when he got his flat, had to stop for a new tire and disagreed with his crew's decision to change only two and not all four. That's where Busch would typically unload on crew chief Dave Rogers. Instead, he simply scolded Rogers. He then calmly offered advice when a caution moments later gave them a chance to salvage the setback.
A blown engine 10 laps later, however, ended his day at his home track. As Busch climbed from his car, viewers braced for his reaction. But, for the second time in two days, he was a total pro.
"I've been blowing tires, mowing grass, knocking walls down and setting balls of fire down the backstretch in both races this weekend," he said. "It might be good just to get out of here and come back and try again next year."
Then came Stewart, who led a race-high 163 laps. A rare mistake on pit road brought a damaging penalty, taking him from the lead to 24th place. He drove his way back to 16th and needed a two-tire change on the next caution to reclaim the lead.
But there was one more pit stop, and that tire strategy meant he'd have to change all four the next time. That final stop was a long one, and he was forced to settle for second.
But there was no explosion.
Busch might simply be growing up. He got married during the off-season. He's also settling into his second year of owning a Truck Series team, and last year's rocky first season taught him how to deal with sponsorship issues, financial problems and a new level of responsibility.
It seems as if the light is finally on, and Busch is trying his hardest not to be his own worst enemy.
Stewart's not as simple. He was always able to succeed despite himself, but it's been five years since his last championship and the wins are far harder to come by at this stage of his career.
His many business ventures have made him a team owner, track operator and race promoter. That's created a desire to keep things stable.
It's far too early in the season to declare either driver a truly changed man, but both are certainly trying. And while some might miss their entertaining explosions, both will likely find their new approach will make life easier both on and off the track.