From Jimmie Johnson trying to capitalize on the opportunity of a lifetime to Tony Stewart taking the gamble of a lifetime, NASCAR’s 60th anniversary season that begins Sunday with the Daytona 500 has an abundance of intriguing story lines.

But looming over it all is a dark cloud of economic uncertainty that affects the cars on the racetrack, the men who work on and drive them, the companies that sponsor them and the fans who pay to watch them.

“Over the last several years, we were all sort of living oblivious to the perils of what we were to face and what we’re facing now,” driver Dale Earnhardt Jr. said. “We stopped paying attention to the little things, and it’s sort of biting a bunch of people in the butt now.”

In the three months since Johnson put the finishing touches on his record-tying third consecutive Sprint Cup championship, the sagging economy has resulted in a flurry of layoffs, mergers and strategic alliances that have brought a seismic shift to the NASCAR landscape.

With the U.S. automobile industry struggling for survival, the Big Three automakers all have cut their NASCAR budgets, but thus far none has threatened to withdraw. Japanese company Toyota also is reporting record losses.

“There is probably not anything on this earth Toyota is involved with now that is not under some level of review,” said Lee White, president of Toyota Racing Development. “If contracts have expired, it’s very likely they have not been renewed — or if they are being renewed, they are certainly being renegotiated.”

Several longtime sponsors are experiencing hard times and title sponsor Sprint Nextel last month announced 8,000 layoffs in an effort to trim $1.2 billion in labor costs.

For its part, other than putting limits on testing as a cost-cutting measure, NASCAR has chosen to let each of its constituencies — from television partners to track owners to the individual teams — deal with the situation as they deem necessary.

“There’s some things we can’t help them with,” NASCAR president Mike Helton said. “There’s some things we give them the recipe to help themselves and it’s up to them to see how the pie comes out of the oven.”

Among the casualties are two of the sport’s most venerable names, Petty Enterprises and Dale Earnhardt Inc., which were forced to surrender their individual identity in mergers with Gillett Evernham Motorsports and Ganassi Racing, respectively.

What hasn’t changed is the hierarchy of the sport as Hendrick Motorsports, Roush Fenway Racing, Richard Childress Racing and Joe Gibbs Racing all return largely intact. Drivers from those four teams claimed all 12 positions in last year’s Chase for the Championship and are poised to do so again.

Hoping to crack that foursome is Stewart, who left the security of Joe Gibbs Racing after winning two championships and 33 races in 10 years to become an owner-driver at Stewart-Haas Racing. The Columbus, Ind., native hired as a teammate fellow Hoosier Ryan Newman (South Bend), who won last year’s Daytona 500 driving for Penske Racing.

“I don’t think it’s for everybody,” Stewart said of his dual roles. “This is what I do. This is all I do. Other guys, when they get away from the racing on Sunday night, they do something totally different. I’m not really that way.”

Rookie Joey Logano, 18, as he takes over for Stewart and tries to become the youngest winner ever.

Jeff Gordon as he looks to bounce back from his first winless season since 1993.

Mark Martin as he joins Hendrick Motorsports and at age 50 takes another run at a championship.

Kyle Busch as he tries to put last year’s Chase collapse behind him and exceed last year’s total of 21 wins across three NASCAR series.

Not to be lost amid all the uncertainty is Johnson’s bid for an unprecedented four titles in a row. Carl Edwards, who finished 69 points behind despite winning nine races to Johnson’s seven last year, is the trendy pick to end the streak.

“If you look at the odds, it’s certainly stacked up against us,” Johnson said. “It’s never been done before. If it does happen, I don’t even know what the hell it would mean. It would just be off the charts.”