Out on track immediately after Red Bull Racing launched their 2011 challenger at the Spanish circuit, Vettel's pace improved throughout the day, resulting in the reigning World Champion finishing the day at the top of the timesheets.The German crossed the line with a 1:13.769, however, also demonstrated a more consistent pace over longer runs, lapping in the 1:15.8s to 1:15.9s.
Another German was right behind him on the timesheets with Nico Hulkenberg impressing his Force India team bosses.
Hulkenberg, who joined the team just days ago as their official test and reserve driver, was in action in last year's VJM-03. He finished the day 0.169s behind Vettel.
Gary Paffett, another driver using last year's car in order for his McLaren team to focus on Pirelli tyre testing, was third quickest ahead of Paul di Resta - Force India's new 2011 driver.
Fernando Alonso had a mixed day. Although he started at the top of the timesheets, the Spaniard dropped to fifth by the close of play, 0.784s behind Vettel.
The Ferrari driver also encountered a minor problem with his new F150 in the morning's session while his day ended with him stopping out on track on the final corner of the day's final lap.
Kamui Kobayashi made a solid start to Sauber's C30's preparations, claiming sixth place ahead of new Virgin signing Jerome D'Ambrosio. The latter was driving a modified version of last year's VR01.
Vitaly Petrov was another putting his team's new car through its pace. However, he amassed just 28 laps in Renault's R31.
Michael Schumacher had his first taste of the Merc GP W02 in the last hour of testing, completing 15 laps on his way to a 1:16.450.
The German, who was down to test in the afternoon, had his running cut short after team-mate Nico Rosberg, who was in action during the morning session, stopped out on track, bringing out the day's - and year's - first red flag. Rosberg, who had suffered a hydraulic problem, finished P13, 4.5s down on team-mate.
Toro Rosso and Williams also debuted their 2011 cars on Tuesday with Jaime Alguersuari 10th quickest ahead of Rubens Barrichello. The latter, though, reportedly had a few problems with his KERS unit.
Unofficial Times
01. Sebastian Vettel Red Bull-Renault 1:13.769 93 laps
02. Nico Hulkenberg Force India-Mercedes 1:13.938 + 0.169s 71 laps
03. Gary Paffett McLaren-Mercedes 1:14.292 + 0.523s 91 laps
04. Paul di Resta Force India-Mercedes 1:14.461 + 0.692s 28 laps
05. Fernando Alonso Ferrari 1:14.553 + 0.784s 97 laps
06. Kamui Kobayashi Sauber-Ferrari 1:15.621 + 1.852s 68 laps
07. Jerome D'Ambrosio Virgin-Cosworth 1:16.003 + 2.234s 71 laps
08. Vitaly Petrov Renault 1:16.351 + 2.582s 28 laps
09. Michael Schumacher Mercedes 1:16.450 + 2.681s 15 laps
10. Jaime Alguersuari Toro Rosso-Ferrari 1:17.214 + 3.445s 19 laps
11. Rubens Barrichello Williams-Cosworth 1:17.335 + 3.566s 77 laps
12. Narain Karthikeyan HRT-Cosworth 1:18.020 + 4.251s 45 laps
13. Nico Rosberg Mercedes 1:19.930 + 6.161s 9 laps
Source: Planet-F1
