Nico Rosberg admitted it had been a tricky day on track after he set the pace for Mercedes on the final day of pre-season testing before the F1 season gets underway in Australia later this month.
Rosberg was one of only three drivers to set a lap time over the course of the day at Catalunya, with improved conditions late on allowing him to complete a grand total of 35 laps.
Despite the conditions, Rosberg was able to complete a limited programme and gain further knowledge of the Pirelli wet tyres and he said he was happy with the progress Mercedes has made now testing is at an end.
"It was tricky out there today; there wasn't a lot of grip, but it was really useful to get the experience on the Pirelli wet tyres,” he said. “We have made a lot of progress over the four tests this winter and it's really nice to see that things are going in the right direction. We have taken a giant step forwards and we are on the up for sure, and all credit to the team for getting the upgrades on the car and, most importantly, to see that they are working as expected."
"We made the big step we had calculated," concurred Mercedes-Benz Motorsport Vice-President Norbert Haug.
Team-mate Michael Schumacher was also in action, albeit only for five laps during the morning as he completed a series of one lap runs to gain some knowledge of the wet tyres himself.
Like Ferrari's Fernando Alonso, Schumacher failed to set a lap time.
"It was good to complete a few laps out there this morning and try out the Pirelli wet tyres. There was obviously a limit to what we could achieve, but we made good use of the time by working through our race procedures. It's been a good week here in Barcelona and we're certainly happy with our position going into the first race of the season."