The German arrives for the inaugural South Korean Grand Prix, a race that was looking doubtful only a few weeks ago, fresh from winning in Japan and eager to pile more pressure on teammate and championship leader Mark Webber.

Vettel, the only one of the five Formula One title contenders who has yet to lead the championship this season, is 14 points behind the pace-setting Australian and level with Ferrari's Fernando Alonso.

After Korea, there are just two races left and none of the contenders can afford any mistakes on what could be a slippery new surface. Vettel is the current betting favorite for the race, Webber for the title.

"In the last few races he (Vettel) has driven extremely well, he's built a bit of momentum back into his campaign and got himself back into contention," Red Bull team principal Christian Horner said after Suzuka.

"Mark has been banging in podiums... and it's going to be about consistency in the remaining three races between the title protagonists."   The Red Bull duo finished one-two at Suzuka and the team, who also lead McLaren in the constructors' standings by 45 points, are determined there will be no favoritism.

"As a team we are trying our best to support both drivers equally," Horner added.

The Yeongam circuit — a four-hour drive southwest of Seoul — is still rough around the edges with the final layer of asphalt laid less than two weeks ago in a race against time and with the threat of cancelation hanging over the event.

"Last month I didn't think it would be finished," Formula One supremo Bernie Ecclestone said this week. "And it would have been canceled then, for sure. But the track has been inspected and passed. Everything's OK."   All the drivers will be starting from scratch in Friday practice.

"I am pretty excited," Vettel, 23, said on the team website (www.redbullracing.com).

"It's a new race track which means none of us have been there before. While I know the race will take place, I can't really say anything about the track itself until Friday."   

McLaren and Ferrari will hope the first sector, with long straights into slow hairpins, will favor their cars over the Red Bulls while the championship leaders can expect to be quicker through the second and third parts.

McLaren's Lewis Hamilton, the 2008 champion who has had a miserable recent run of retirements and disappointment, and reigning champion Jenson Button are both hoping new parts will help get their car back on top.

"We've made some improvements to the parts we tested in Suzuka, and it's looking likely that we'll run the new parts on Friday in Korea," said Button, fifth and 31 points behind Webber, in a team preview.

"As with all our upgrades, we are pushing the envelope, so I'm optimistic that the tests will be positive and that we'll be able to race the new components."   Hamilton, fourth and 28 points off the pace, said first impressions on the McLaren simulator had been positive.

"On paper, the track should suit our car quite well," he said. "The first sector is all about good end-of-straight speeds and strong performance under heavy braking, both key characteristics of our car.

"And the middle sector is fast and flowing; it's the kind of place where you want a car with a good balance and good downforce. I think it'll reward commitment," the 25-year-old added.