The Brazilian lapped 0.151s quicker than team mate Michael Schumacher in free testing at the Italian Grand Prix.
Brazilian Rubens Barrichello will begin a new chapter in his record-breaking Formula One career next year as a Williams' driver alongside German rookie Nico Hulkenberg.
Brazilian Rubens Barrichello will get a five-place penalty on the starting grid for Sunday's Malaysian Grand Prix after Brawn GP changed his car's gearbox after practice on Friday. The decision dealt a blow to his new team's chances of repeating their stunning one-two finish in Australia last weekend.
Brazilian Rubens Barrichello won the Italian Grand Prix on Sunday in a Brawn one-two to cut team mate Jenson Button's Formula One lead to 14 points with four races remaining.
"It would be a lack of respect to stop now and say okay, I don't care any more what's happening to Ferrari," said the Brazilian driver
Ferrari's new Formula One car is clearly quicker than last year's, Brazilian Rubens Barrichello said after driving the F2005 for the first time on Tuesday.
The Brazilian was 0.265 seconds quicker than the championship leader who is seeking his eighth win in nine races.
Brazilian Rubens Barrichello ended five years of frustration on Sunday with an emotional victory for championship leaders Brawn GP in the European Grand Prix. Barrichello, whose last victory was with Ferrari in China in September 2004, beat McLaren's world champion Lewis Hamilton by 2.3 seconds on a sizzling afternoon at the Valencia street circuit.
Barrichello took the chequered flag for the first time since last season's final race in Japan, a mere 1.3 seconds ahead of team mate Michael Schumacher.
Brazilian Rubens Barrichello seized pole position on Saturday for his home grand prix in a nightmare scenario for championship-leading Brawn team mate Jenson Button.
Ferrari introduced their F2005 at the last race in Bahrain, advancing its debut in response to Renault's domination
Brazilian Rubens Barrichello won the Italian Grand Prix on Sunday in a Brawn one-two to cut team mate Jenson Button's Formula One lead to 14 points with four races remaining.
Renault's Fernando Alonso made his peace with future Ferrari team mate Felipe Massa on Friday before setting the pace in free practice for the Brazilian Grand Prix at Interlagos. While the Spaniard lapped with a best time of one minute 12.314 seconds, Brazilian Rubens Barrichello was the fastest of the three championship contenders ahead of what could be a title-deciding race on Sunday.
Ferrari kept Brazilian Rubens Barrichello off the track for Saturday's opening practice at the Bahrain Grand Prix after having to rebuild his new car's gearbox.
Juan Pablo Montoya accused Rubens Barrichello of illegally blocking him in order to help Ferrari team mate Michael Schumacher.
Brawn GP driver Rubens Barrichello said on Tuesday he is in talks with Williams and is sure to remain in Formula One next season. The Brazilian denied, however, he has already signed a deal with Williams, saying he is also in discussions to renew with his present team.
Rubens Barrichello wore his feelings on his chest, if not his sleeve, at the Hungarian Grand Prix on Thursday when he turned up for duty in a 'Mr Happy' T-shirt. After angrily accusing his championship-leading Brawn GP Formula One team of costing him victory at the previous race in Germany, the Brazilian made clear that he has calmed down and made his peace with the world.
Germany's Sebastian Vettel ran away with the British Grand Prix in a Red Bull one-two while championship leader Jenson Button struggled home in sixth place on Sunday.
Michael Schumacher apologised to Rubens Barrichello by text on Thursday for almost forcing his former Ferrari team mate into a wall at this month's Hungarian Grand Prix.
The Briton expressed his disappointment that the Brazilian had decided to leave Ferrari for BAR at the end of the season.
Rubens Barrichello accused his Brawn GP team of losing him the German Grand Prix in Nuerburgring on Sunday and said he did not want to hear any excuses from them. In an extraordinary outburst, the Brazilian told BBC television that the afternoon had been "a good show from the team on how to lose a race."
The Ferrari driver took the honours as F1 experienced single-shot qualifying for the first time.
Germany's Sebastian Vettel ran away with the British Grand Prix in a Red Bull one-two while championship leader Jenson Button struggled home in sixth place on Sunday. Australian Mark Webber finished runner-up, 15.1 seconds behind the 21-year-old, with Brazilian Rubens Barrichello in third place for Brawn GP.
Rubens Barrichello ruled out playing a subservient role to Brawn GP team mate Jenson Button on Sunday and said he would quit Formula One if he got the slightest sniff that the Briton is being favoured. The Brazilian, who finished second to the championship leader after a sudden strategy switch at the Spanish Grand Prix, told a Speed TV reporter he would "hang up his helmet" if he suspected the team are not giving him an equal chance.
