Renault believe they are well placed to continue their early-season form at the San Marino Grand Prix on 24 April.
Renault have three wins from three races so far this season
Fernando Alonso will take a 10-point lead to Imola, with his home race in Spain to follow two weeks later.
And Renault's chief test engineer Christian Silk said work in Barcelona this week had been "very successful".
"We've found good set-up directions for Barcelona, but also for Imola, and we continue to make good progress in our understanding of the car," said Silk.
Renault have emerged as the team to beat this season, picking up 36 points in the first three races, with two wins for Alonso and one for Giancarlo Fisichella.
The Anglo-French team joined most of their rivals for testing in Barcelona, and believe they have made another positive step.
"The team made a big effort to bring our programme forward, and we have had three dry, productive days' running," said Silk.
"Fernando has experienced few problems and completed plenty of miles, working on promising tyre developments and exploring the car's set-up.
"Giancarlo's week has been more disrupted, but he will drive again next week which will allow him to get more seat time in the car."