Sebastian Vettel began life as a Red Bull Racing driver in the perfect manner after topping the times on the second day of testing at Barcelona.
The German driver led a quartet of Red Bull cars, as Takuma Sato was the fastest of the three Toro Rossos that finished behind Vettel.
The Red Bull Racing driver was the only man capable of lapping the Spanish track in less than 80 seconds, posting a best time of 1:19.751 to outpace Sato, quickest yesterday, by nearly four tenths.
Sebastien Bourdais and Sebastien Buemi proved the battle for the 2009 Toro Rosso seats is a tight one, finishing right behind Sato.
"I have really enjoyed the test and it was great to be back in the car," said Sato. "The last test in September was a little disappointing, because I could do only 3 hours, as it rained in the afternoon.
"But this test has been great - I have now done my first full day's driving in 7 months and completed a total of 200 laps. The car has worked really well and felt great to drive.
"I enjoyed working with the team and it was very interesting for me to see how the engineers work. It was a great experience and chance for me and so I would like to say a big thanks to Red Bull and Mr. Mateschitz, as well as to the Scuderia Toro Rosso team."
McLaren's test driver Gary Paffett completed the top five as he worked with both the MP-23 and the MP4-23K, the KERS test car. The Briton was only the driver working for McLaren as Pedro de la Rosa was testing for the Force India team.
Paffett moved to the MP4-23 after his KERS car suffered a minor oil leak that prompted the team to take a precautionary switch.
BMW Sauber's Robert Kubica was sixth fastest as his team continue to focus on work with their interim cars fitted with 2009 aero packages.
"Of course we lose a lot of downforce compared to the 2008 car," Kubica said. "But because we are back from grooved to slick tyres, we have substantially more grip in slow corners.
"So with some more development I don't think there will be too big a difference between the 2009 and 2008 cars."
Nico Rosberg was the only man in charge of testing duties for Williams, the German finishing in seventh, ahead of Jenson Button in the first of the Hondas.
The second was again driven by Lucas di Grassi, who finished as tenth quickest after 110 laps. Tomorrow di Grassi will handle his car over to Bruno Senna.
The Renault team worked again with Nelson Piquet and Giedo van der Garde, both men focusing mainly on collection of data from the slick Bridgestone tyres.
"It was a similar day to yesterday as we continued learning about the slick tyres and working on the car set-up by trying to simulate next year's settings," said Piquet.
"It was a bit cooler than yesterday, but the track conditions were not too bad and we didn't have any problems with the car, which allowed us to get a good number of laps in. So a positive second day, which we can build on tomorrow."
Ferrari's Luca Badoer and Marc Gene were 12th and 13th respectively, the Italian focusing mainly on engine and gearbox reliability while the Spaniard did set-up work.
"We got rid of as many things as possible, to try to create the downforce we'll have the next season," said the Spaniard.
"But the main thing is the slicks. I couldn't directly compare them, but the first feeling is that the grip delivered by the new tyres compensates the lower downforce.
"Personally I'm working with the car's set-up, trying to understand the handling with the new tyres. Luca is working on the reliability, especially of the engine, because in the next season it has to live 50% longer."
Compatriot de la Rosa, testing a Ferrari-powered Force India for the first time, finished at the bottom of the times after 86 laps.
Today's times:
Pos Driver Team Time Laps 1. Vettel Red Bull-Renault (B) 1:19.751 70 2. Sato Toro Rosso-Ferrari (B) 1:20.017 79 3. Bourdais Toro Rosso-Ferrari (B) 1:20.034 48 4. Buemi Toro Rosso-Ferrari (B) 1:20.223 99 5. Paffett McLaren-Mercedes (B) 1:21.340 31 6. Kubica BMW-Sauber (B) 1:21.521 76 7. Rosberg Williams-Toyota (B) 1:21.525 113 8. Button Honda (B) 1:21.770 110 9. Sutil Force India-Ferrari (B) 1:22.073 58 10. di Grassi Honda (B) 1:22.283 110 11. Piquet Renault (B) 1:22.348 85 12. Badoer Ferrari (B) 1:22.425 127 13. Gene Ferrari (B) 1:22.772 31 14. Heidfeld BMW-Sauber (B) 1:22.945 81 15. van der Garde Renault (B) 1:23.250 37 16. de la Rosa Force India-Ferrari (B) 1:23.499 86
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