"We should be very strong from now to the end of the year," the Brazilian said on Sunday.
However, far less cheerful was Michael Schumacher, Rubens' world champion teammate.
"Rubens drove a really good race," said the German, "so surely we have made a little step in the right direction."
Finishing fifth, though, Schumacher's Bridgestone tyres were badly worn at the end, and he demonstrated neither race nor qualifying pace all weekend.
"Usually we're slower in qualifying and quicker in the race," he agreed, "but this time we were pretty slow in both.
"The whole package is not good enough -- everything must work perfectly in harmony and that is not the case. But the beauty of sport is that hope dies last." -GMM