The longest-running crew chief-driver tandem in NASCAR enjoyed a looser moment without the creative tension that carried Johnson and Knaus to a record fourth consecutive Sprint Cup championship.

There was the Ford 400 several hours earlier at Homestead-Miami Speedway, where Johnson bordered on histrionics fretting about passing slower cars and Knaus chewed out his team for a slow pit stop. Or the night at Lowe's Motor Speedway last month when Johnson threatened to strangle Knaus after being coaxed on the team radio to pedal his No. 48 Chevrolet a tad faster. Though he married wife Chandra five years ago, Johnson, 34, says his eight-season partnership with Knaus is its own version of an old married couple.

"Channie and I joke all the time he's my second wife except he takes more work," Johnson says, laughing. "A ton of work."

The mellow driver from El Cajon, Calif., shares few traits with the meticulous, high-strung leader from Rockford, Ill. Knaus, 38, says the relationship works because "we can get mad at each other. We've got a cool dynamic."

This season, their roles have reversed somewhat. Encouraged by team owner Rick Hendrick, Johnson has vented more often on the radio because "if I hold on to things, I explode," while Knaus has tried to play soothsayer. But sometimes that's backfired and led to sniping from Johnson, who knows Knaus' sharp-tongued style too well to find it sincere.

ESPN analyst Ray Evernham, who led Jeff Gordon to three titles and hired Knaus at Hendrick Motorsports, says crew chief-driver conflict can be positive.

"It's not like you're best friends," Evernham says. "It's no different than saying to your brother, 'What did you do that for, idiot?' Chad knows no one could drive the 48 better than Jimmie. Jimmie knows no one can prepare that car better than Chad. That creates the bond."

How long will the bond last? Johnson recently re-signed through 2013 and plans to race well beyond that. Knaus is signed through 2010 and hinted Sunday of ending longtime bachelorhood so "10 years from now when I'm sitting on my patio with my son or daughter or wife, I can reflect."

"Retired, son and daughter?" Johnson ribbed. "You have a lot to do in 10 years, buddy." Replied Knaus, "It's all coming, man."

Enlarge By Sam Greenwood, Getty Images Jimmie Johnson and crew chief Chad Knaus have been together for eight seasons, the last four all resulting in Sprint Cup championships.