Nearly half of the 43-car starting field for the CARQUEST Auto Parts 300 NASCAR Busch Series race on Saturday night, May 27, at Charlotte Motor Speedway could be comprised of drivers who will also compete in the Coca-Cola 600 NEXTEL Cup Series event on Sunday evening, May 28.

With NASCAR placing limitations on testing, "double dipping" is the sport's hottest trend as numerous drivers and teams are using Busch Series events to improve their chances of a top finish in the NEXTEL Cup races.

"Having Cup drivers in Busch races is a mixed blessing," said H.A. "Humpy" Wheeler, president and general manager of Charlotte Motor Speedway. "On one hand you need them to sell tickets because you would only have about half a crowd without them. On the other hand, they get a lot of the money the Busch guys would normally get.

"In the old days, Busch races were run with well known short track stars that pulled fans from those tracks mostly concentrated in the South," Wheeler added. "We didn't need Cup drivers then. However, today these drivers come from all over the country and are not familiar to fans at a lot of the tracks."

Among those scheduled to compete in both the Coca-Cola 600 and CARQUEST Auto Parts 300 are three-time Coca-Cola 600 winner Jimmie Johnson, defending NEXTEL Cup champion Tony Stewart, Mark Martin, Kasey Kahne, Elliott Sadler, Matt Kenseth, Greg Biffle, Jeff Burton, Ryan Newman, Casey Mears, Michael Waltrip and Jamie McMurray.

"Double dipping" has become so popular that seven drivers-Kevin Harvick, Denny Hamlin, Clint Bowyer, J.J. Yeley, Kyle Busch, Carl Edwards and Reed Sorenson-are chasing championships in both series.

When Harvick captured the 2001 Busch Series title while also running all but the Daytona 500 on the NEXTEL Cup side, there were a number of weekends when he spent nearly as much time on airplanes as he did on the race track. This year, however, there are several more weekends when the two series are at the same track, lessening the logistical strain.

"It's a lot easier than it was in 2001, I think," Harvick said about chasing two championships. "I think we'll be fine as long as the weather cooperates.

"With the limited testing and the limited tire availability, it will be important to understand the tires and understand cambers and tire wear and air pressures and things like that," the Bakersfield, Calif., native added. "Those are the main reasons we're doing it."

Edwards won Raybestos Rookie of the Year honors in the Busch Series last year, while also qualifying for the Chase for the NASCAR NEXTEL Cup, proving as Harvick did in 2001 that a driver can be successful while running both series.

"Running both series helped me in a bunch of ways," Edwards said. "The first thing is I just got to race more. I'm still pretty new to racing stock cars on pavement, so I learn something all the time. The other thing is that it's just fun. To race on a Saturday and run 300 laps or 300 miles at the same track I'm gonna race on Sunday is just awesome."

The toughest challenge of "double dipping" is scheduling, especially when the two series are in different states on the same weekend.

"I had to bite the bullet and buy my own plane," said Hamlin. "It's a lot for me in a short amount of time, but I'm pretty excited about it."

"I'm sure there will be times where you're just going to be worn out," noted Sorenson. "I think if you run well, it makes it a little bit easier to go through those times. If you're running well and you're tired and fatigued, it's all worth it. I think the tough times will be if you have a couple bad runs in a row and you're all worn out at the same time."

Yeley believes running both series simply makes things twice as nice.

"It's amazing to me now just thinking about it-just the different feel that I have in the race car now compared to what I had this time last year," Yeley explained. "I can drive a car that's a lot looser or I can stay out of trouble. I can put the car in positions that I probably couldn't have gotten out of last year, so just having seat time and getting used to these cars, knowing what they want and what they don't want has been the biggest thing for me."

Running both series might appear mentally draining, but Bowyer knows it's helping make him a better driver.

"It's actually been a help. It forces you to stay more focused and concentrate on what you're supposed to be doing, just because you're in the car so much," he said. "You're thinking about how to be better and how you can get better."

Tickets for all May events at Charlotte Motor Speedway, including the May 27 CARQUEST Auto Parts 300 and May 28 Coca-Cola 600, can be purchased by calling the Charlotte Motor Speedway ticket office at 1-800-455-FANS or online here.