Felipe Massa says it was an intriguing day spent amassing data for Williams using its experimental double wing at the in-season test at the Circuit de Catalunya.

The Brazilian, whose future in the sport is under question after the current season concludes, picked up from where development driver Alex Lynn left off on the opening day running the new double-plated rear wing.

The wing, which would be illegal under current technical regulations but a possibility for the 2017 rule changes, had turned heads in the paddock on Tuesday and Massa spent the entire day running it gathering data for the team to digest at its Grove headquarters.

"It was an interesting test," Massa said. "We worked on so many things for developing and improving the car on the aero side, which was our biggest aim for these two days. We tried a lot of different things for the future so it has been an important two days and key to get a lot of mileage."

Rod Nelson, Chief Test & Support Engineer at Williams, says he's satisfied with the work produced by both Lynn and Massa which will enable them to push ahead with updates for both this year and next year's car.

"We spent most of the time with Felipe looking at the aero performance of the current car and looking into development work for next year as well," Nelson said. "It was a fairly positive day with a clear direction, and we'll be using that data to feed back into the development work we are doing at the moment for this year's and next year's car."