FUJI, Japan, Sept 28 (Reuters) - Formula One drivers are relishing the challenge of a revamped Fuji Speedway after free practice on Friday threw up a few high-speed surprises.

The Fuji circuit mixes slow corners with the longest main straight in Formula One, set to allow for plenty of overtaking in Sunday's Japanese Grand Prix.

"We knew the straight was very long but in the car it feels even longer," said double world champion Fernando Alonso, who was second fastest behind McLaren team mate Lewis Hamilton.

"All the circuit is very challenging and quite difficult because you need to guess when you have to turn in...It's
difficult but we like difficult circuits.

"I enjoy having new tracks in Formula One because we all know the traditional circuits and we test and race there many times. New circuits are always more fun to drive."

Spaniard Alonso trails British rookie Hamilton by two points in the drivers' championship with three races left.

Ferrari's Felipe Massa, 20 points behind Hamilton and still mathematically in the running, also gave Fuji the thumbs-up.

"On this interesting track, it is not easy to find the right balance between the slower section and long main
straight," said the Brazilian.

"We improved the set-up during the day but there is still much to do. However, the first impressions are positive and I think we can be competitive."

Toyota-owned Fuji, boasting the majestic backdrop of a snow-capped Mount Fuji, is returning to the Formula One
calendar after a 30-year absence, replacing Honda's Suzuka circuit.

Kimi Raikkonen, 13 points adrift of Hamilton, echoed Ferrari team mate Massa's assessment.

"It is demanding but enjoyable to drive," said the Finn, winner of the last race in Belgium.

"It's quite difficult to find the best set-up on this track, especially for the final sector."