The reigning world champion set a quickest time of 1:23.315, over a second quicker than the fastest time on Friday, as the team opted to simulate a race weekend in a single day, giving an insight into the RB7Ã¢â‚¬â„¢s potential pace ahead of the 2011 season as Vettel easily established himself at the top of the time sheets.
Toro Rosso also continued their good pre-season form as Jaime Alguersuari was second quickest in the STR6, just two tenths slower than VettelÃ¢â‚¬â„¢s time courtesy of a three-lap run late in the day after the Spaniard worked through a programme of short stints before a longer run in the middle of the day.
Ferrari suffered their first reliability problem of the year as an electrical problem left Fernando Alonso stranded on track. But while that was speedily resolved, additional mechanical problems hampered their progress before Alonso was able to do some decent long runs, with his quickest time of 1:23.978 coming in the final half hour of the day to secure third quickest.
Rubens Barrichello enjoyed a trouble-free day to complete 118 laps in the FW33, with 1:24.008 enough for fourth quickest.
Nick Heidfeld got a solid run out in the R31 in the afternoon to complete 41 laps to record the fifth quickest lap time, a 1:24.242, with a late surge as Renault evaluated suspension programmes as well as new and scrubbed sets of tyres.
Kamui Kobayashi began the day with a series of long runs in SauberÃ¢â‚¬â„¢s C30, before a short five-lap run in the afternoon elevated him to sixth place with a time of 1:24.243 for sixth quickest on his way to 125 laps as the team worked through tyre programmes.
Nico Rosberg appeared to be off the pace as the Mercedes W02 completed over 600kms with a quickest time of 1:24.730 for seventh, focussing on their KERS system, set-ups and aerodynamic evaluations in the morning, before running a second full race simulation, with five pit-stops in the afternoon.
McLaren again lost a lot of time as a hydraulic failure kept Jenson Button off track in the morning, and again in the afternoon session as the problem returned, while a lack of spare parts again hampered efforts to get the car up to speed.
Despite being behind their rivals in terms of distance covered, Button was able to put in a time of 1:24.923 for eighth quickest as he completed 54 laps.
Paul di Resta completed 80 laps over a variety of lengths and set-ups and impressed again on his way to the ninth quickest time of 1:25.194 with only a limited period of downtime to hamper the teamÃ¢â‚¬â„¢s programme after FridayÃ¢â‚¬â„¢s problems.
Heikki Kovalainen led Team LotusÃ¢â‚¬â„¢ testing programme as the team had to overcome minor problems with a water leak and fuel pressure, but was unable to complete a race simulation programme with his quickest time of 1:26.420 coming on lap 17.
The afternoon session saw Kovalainen complete runs of between five and eight laps as the team evaluated different tyre compounds.
Vitaly Petrov got the chance to get some miles in after mechanical problems sidelined Renault on Friday. The Russian completed 41 laps in the morning, with a time of 1:26.884 eventually placing him 11th quickest, over two seconds slower than Heidfeld.
Vitantonio Liuzzi got his first chance to drive Hispania RacingÃ¢â‚¬â„¢s 2010 car and set a quickest lap of 1:27.044. The Italian is in the running to partner Narain Karthikeyan at the Spanish team, and his programme aimed to get him used to the car, the team, and PirelliÃ¢â‚¬â„¢s tyres.
Timo Glock focused on a number of short runs in the morning to try out different gearbox settings, and run pit-stop practices in the morning session before switching to set-up runs in the afternoon with Virgin RacingÃ¢â‚¬â„¢s MVR-02 on new and used tyres.
Ricardo Teixeira got an opportunity to test the T128 for the first time after lunch before Kovalainen took over, completing 26 laps with a quickest time of 1:31.584 on lap 22.
The 26-year-old, who helped the team in Valencia with filming made no mistakes and consistently improved on the medium compound tyre.
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BIOGRAPHY: Georginio Wijnaldum