The Finn completed forty laps and ended the day in fourth position.
"It was good to get behind the wheel of a Formula 1 car again," he said.
"The E21 feels quite good so far, even if the balance isn’t quite to my liking yet. That didn’t stop us going through the programme we wanted to do which had a lot of aero runs in it."
"We know the car can go faster, we were just running through what we needed to achieve. It’s a shame that we had a clutch issue at the end of the day, but that’s why we come testing so we can find these problems and fix them."