Daniel Juncadella F1 Williams test extended into second day

The Mercedes DTM racer completed 55 laps, ending the day fifth fastest, but lost running during the morning because of bodywork problems caused by an aero rake disturbing the airflow in an unexpected way.

Originally, Williams planned to run throughout tomorrow with race driver Pastor Maldonado, but it has been decided that Juncadella will take over the car from the Venezuelan in the second half of the afternoon.

"Because the morning was cut short due to some issues, I didn't get all the running that was planned," Juncadella told AUTOSPORT. "They are giving me a chance to do some laps tomorrow.

"Running the same day as Pastor, although we have different programmes, we have the real comparison on track.

"That's a pretty good thing because I can really learn from him in the same day, so it's a good chance."

Even though there were car problems, Juncadella was happy with his performance.

He was able to complete both short and long runs, as well as doing aerodynamic runs for the team as it evaluates parts.

"I enjoyed this opportunity a lot and it's always great to drive a Formula 1 car," he said.

"From the first lap on, I had a smile on my face because the speed that these cars have is pretty impressive.

"Obviously you are doing aero stuff, you can see all the cars doing out-laps and in-laps and we focused on that at the beginning of the day.

"We did a few new tyre runs and also a long run to evaluate myself and give me some confidence with the car on both sets of tyres.

"I felt really good with the car and when we had the new tyres, I took the most from them for my experience right now on the first lap, which is usually where you have to make the difference and use the peak of the tyre.

"When we did long runs, I was pretty consistent so we are all very happy."