Fernando Alonso believes Red Bull is still favourite for the Korean GP, although the Ferrari driver reckons its advantage will not be as big as at Suzuka.
Sebastian Vettel led team-mate Mark Webber to a commanding one-two in Japan two weeks ago, as the Suzuka circuit proved to be a perfect match for the Red Bull car.
Alonso, who finished today's practice session in second place behind Webber, reckons the nature of the Korean circuit should mean Red Bull is closer, but still quickest.
"On Friday we don't normally look into the times, but we knew or we felt that it was a Red Bull track and confirmed that on Saturday and Sunday," said Alonso of Suzuka.
"Here, as I said, Friday is not very important, but we feel that maybe it's not as easy as it was for Red Bull in Suzuka, even if they are still being the favourites."
The Spanish driver admitted he enjoyed the new circuit, although he said the final corner could cause trouble.
"I like turns 4, 5 and 6, the three corners together at the end of the first straight, they are very interesting," he said.
"I think there are possibilities to overtake on turn 3 and turn 4 as well. And then the worse corner is the last one, or before the last corner, the inside kerb, we are touching quite a lot there and you hit very hard with the chassis."
Team-mate Felipe Massa, sixth fastest today, believes Ferrari will be strong this weekend, despite his complaints over the radio that his was car "undriveable" in the final part of the track.
"It's undriveable in terms of set-up," he said. "I was struggling a lot to make the tyres work well, and that's why I said that. But anyway, the car looks competitive."