Fresh from the conclusion of his title-winning GP2 campaign, Romain Grosjean has completed two days of testing with the Renault team to familiarise himself with F1 machinery again.

Grosjean, now the official Lotus Renault GP reserve driver after Bruno Senna was promoted into a race seat, completed 600km of running in Valencia at the wheel of the R29 he raced during the latter stages of 2009.

Following two days of trouble-free running, Grosjean admitted he was pleased to be back behind the wheel of an F1 machine.

"It is always fantastic to get back in an F1 car," he said. "The aim of the drive was to get me used to drive an F1 car again. We did some qualifying running in the morning and some long running in the afternoon. We also did some pit stop practices. It was very good for the fitness; I was very pleased and I did enjoy working with the team a lot.

"It felt different compared to 2009 because I am more experienced now. I enjoyed the car from the moment I jumped in and I enjoyed working with the engineers. We had a good time in Valencia and everybody enjoyed it."

Grosjean has been linked with a return to the F1 grid next season, with Renault team boss Eric Boullier making no secret of his desire to find a seat for the 25 year old.