The Pole drove a Renault-powered Lotus E20 car painted in Renault colours at the Valencia circuit on Tuesday, completing 115 laps as he conducted several evaluations with different fuel loads.

Kubica had not driven F1 machinery since his career was interrupted by a rallying crash that caused severe damage to his right hand in 2011.

The 32-year-old admitted the test was an emotional moment for him and, although he was proud of his work, he conceded the run showed what he had lost during his time away from the sport.

"For me, it has been an important day from an emotional point of view," said Kubica. "It has been a long time away from the paddock and I have been through difficult periods, I kept working hard and a few years ago I felt it was impossible.

"I have mixed feelings, I am proud with what I achieved today, but also it shows what I have lost.

"I don't know what the future will bring, but I know one thing, after working for more than one year to prepare for this, I ran with good pace and consistent in difficult conditions.

"It is not easy after six years, but I knew I could do the job and I can be satisfied. I appreciate the opportunity. Renault gave me my first F1 test in 2005, so I appreciate another test this time around."

Renault's sporting director Alan Permane said that Kubica's character had changed since he raced for the team in 2010, but said the feedback from the Pole was like "turning back the clock".

Permane labelled Kubica's performance as "great"·.

"It was good to see Robert back in a Formula 1 car. It was a smooth day," he added. "We tried to condense a grand prix weekend into one day, which was interesting for him.

"Robert has changed a little, he is more mellow and he wasn't as pushy when asking for every detail about the set-up of the car! His comments and feedback, however, were like turning the clock back for all of us.

"It is a tricky thing to jump into an F1 car after six years and it was a great performance from him."

Permane insisted, however, that the outing was just a one-off for Kubica.

"This was a one-off event for Robert," he said. "His time with Renault was cut short so abruptly and we perceived such a nice future with him.

"The team was in Valencia testing with Sergey Sirotkin, so it was the perfect opportunity to offer Robert a day in the car and contribute in our way to his recovery."