Vettel back on top as F1 fires up for a new season

Formula One champion Sebastian Vettel showed no signs of winter rust on Tuesday after taking the wraps off his new Red Bull and then lapping faster than anyone else in the first test of 2011.

The 23-year-old German, the sport's youngest ever titleholder, completed 93 laps of the Valencia circuit in the RB7 on a cold but bright day that saw seven of the 12 teams debut cars and get to grips with new tyres and technology.

"It was a good day and I felt comfortable in the car," he said after setting a best lap of one minute 13.769 seconds.

Red Bull, Michael Schumacher's Mercedes GP team, Williams and Toro Rosso all unveiled their new cars at the Ricardo Tormo circuit -- with the first two getting most of the publicity -- while McLaren, Force India, Virgin and HRT gathered tyre data with last year's racers.

Renault, with an original exhaust system that provided a major talking point, and Sauber had already presented their challengers on Monday while Ferrari were first into the limelight with their F150 shown off at Maranello last week.

Malaysian-owned Team Lotus, who had opted not to test on Tuesday in exchange for a day on their own at the Valencia circuit on Friday, had unveiled their car online.

The times, with teams carrying out installation laps and working to iron out gremlins and adapt to the new Pirelli tyres that have replaced the Bridgestones, were of little real significance.

Behind Vettel, the 2010 cars filled the next three places with Germany's Nico Hulkenberg, reserve for Force India, second fastest in 1:13.938

"The feeling is good," Ferrari's Fernando Alonso, fifth and 0.784 off Vettel's pace, told reporters after weaving across the paddock with a mobile phone clamped to his ear as admirers shrieked his name and mobbed around for autographs.

"The biggest priority for this test is to do mileage, to learn about the car and have a lot of data in three days time when we go back to Maranello," added Spain's double world champion, who did more laps (97) than anyone.

"Today was a positive day, with no mechanical problems at all in the car.

"We keep discovering about the new rules, with the rear wing and the KERS, to get used to the system. The tyres degrade a lot and are not very consistent at the moment," he said.

Drivers have to master more buttons on the steering wheel this season, with the return of the KERS kinetic energy recovery systems and a new moveable rear wing that has taken some getting used to.

"It's not the easiest thing to do at the exit of the corners," said Alonso. "It's new buttons on the steering wheel but we start slowly and we've done some practice in the simulator also.

"We started step by step. Some laps we activated the KERS and on others the rear wing. Then we started doing everything at the same time and getting used to it. Now in the afternoon everything was coming automatically."

"(The next test in) Jerez I think will be enough to be completely confident in the new things."

India's Narain Karthikeyan, testing for tail-enders HRT, returned as a full race driver for the first time since 2005 and completed 45 laps.