The IndyCar Series will enter a vital stage at Kentucky Speedway this weekend with just six drivers still in contention for the title going into the Meijer Indy 300.

Scott Dixon currently leads the way for Chip Ganassi Racing with a 65 point lead over Penske's Helio Castroneves, but Dan Wheldon, Tony Kanaan, Ryan Briscoe and Danica Patrick could all still lift the 2008 title.

Dixon however will hope that history repeats itself, with the points leader with four races remaining having taken the title in five of the last seven years, although he admits that Kentucky isn't the easiest circuit on the calendar to kick-start the vital run-in.

"Kentucky is a tough track," he said. "We just tested there, so that might help a little bit since it's only a two-day event. It still comes down to the race, and Helio's always there at the end. You have to make sure you have everything right.

"We've got four races to go and a 65-point lead, but that's very catchable, for Helio especially. For the next four races, the people we're competing against are all really good at those four races. Helio, I think is the real threat. He's been very quick the past few races. They've stepped up their game a lot."

Dixon, a five-time winner this season, has finished second three times in five starts at Kentucky. Castroneves, who has six second-place finishes this season, has a best finish of third at Kentucky.

"Kentucky is a tough track to master, because it's very bumpy and very fast," the Penske man admitted. "There is hardly any banking, so it's always a challenge to make sure we get the right setup on the Team Penske car. The racing is extremely tight with a lot of side-by-side action, which makes for an exciting show for the fans. It seems that the race always comes down to the final laps, and I'm not expecting anything different this year.

"Historically, this hasn't been one of my stronger tracks, but it's my goal to turn that around this year. I have had a solid and consistent year, and we're right there in the championship standings. We'll need a strong finish this weekend as well as a little luck to go our way in order to make up some ground in the points battle. We have a lot of momentum heading into Kentucky; we've won the last four poles and I've finished on the podium the last three races. I certainly think with the way Team Penske has been performing we have it in us to claim the title when all is said and done."

Wheldon and Kanaan are the other two main contenders in terms of the championship crown, with Briscoe and Patrick set to eliminated from the race for the title unless they can close to within 159 points of the lead over the course of the weekend.

The pair have already been involved in one major story this week with Kanaan having been linked with Wheldon's drive before extending his deal with AGR yesterday [Thursday].

With rumours still existing over his future, Wheldon will look to keep his hopes of a second IndyCar crown alive at a venue where he took third place in his championship winning year of 2005.

"You're not always going to have perfect seasons, but I really feel in these last four races, the tracks that we're going to, I feel confident I can make it a strong ending," the Briton reflected. "The thing now is to try to take as many points off Helio as I can. To some degree, I'll always support Scott to make sure the team can win the championship, but at the same time it would be nice to finish the season with a couple more wins.

"These last four races, I want to win, but if the team feels it's a benefit for me to do something to help Scott, then I absolutely will. I like to think I'm a real team player, but at the same time I really want to finish second in the championship. Hopefully, if we can get Scott locked up pretty quick, he can help me do that, too."

Kanaan meanwhile is the only driver in the 26-car field to have won at Kentucky in the past and he said he felt the event would be vital in terms of the battle for the title.

"I had a great time at the Meijer Indy 300 last year, and I fully expect the Team 7-Eleven car to challenge for the pole and the win again," he said. "We know that we have our work cut out for us, though. Those of us in the top four are still fighting for every point. I think the Meijer Indy 300 will be a competitive race and great for the fans."