Nelson Piquet Jr is confident Renault are moving in the right direction after spending Monday testing new aero parts for the R28.

The Brazilian was in action at the Barcelona circuit for Day 1 of a four-day test, where the team experimented with several upgrades to the R28, which included a new front wing design.

Piquet Jr also got familiar with Bridgestone's slick tyres, which will be used during the 2009 F1 Championship.

However, his running was cut short when he brought out the red flags prior to the lunchtime break.

"It was another good day of work. The track conditions were good, so there were no problems there and we had a productive morning," said Piquet Jr after finishing fifth on the timesheets.

"Unfortunately I lost some time in the afternoon and so I did not do as many laps as I would have liked.

"We tried some new things but the more interesting work will come later in the week."

Christian Silk, Renault's chief test engineer, added: "The morning programme ran very well and so it was a solid day of work with the only delay coming at lunchtime.

"The car is working very well and the factory has made a huge effort to get the car ready for this week. We just need to carry on this good work for the rest of the week."