Williams driver Felipe Massa says he is disappointed after a "not very useful" day of running at the Circuit de Barcelona-Catalunya.
Massa was in the new FW38 for a second day but reliability problems limited his track time in the afternoon session, meaning he only managed 54 laps in total.
The Brazilian racer ended the final day of the first test in ninth place with a 1:26.483. He was hoping for more running but was pleased the Grove-based outfit got through important aerodynamic tests in the morning.
"I am not so happy with today – it was not really a useful day," he said. "The most important things was that we carried out our aerodynamic tests this morning, to understand the numbers and everything around the car.
"Unfortunately, we couldn’t run much this afternoon. I had hoped to do more laps than I did."
Rod Nelson, chief test and support engineer at Williams, added: "Today was one of those days I’m afraid. We spent most of the morning doing aerodynamic correlation work which was pretty successful.
"We are getting through our programme day by day. Sadly, we had an issue with one of the car systems over lunchtime and that curtailed a lot of our running this afternoon which we had planned. We know what the issue is, we’ve got a solution, and now we look forward to next week.”
