While Felipe Massa was happy with his P1 on the Jerez timesheets, it was the reliability of his FW36 that really had him smiling.
Like many teams the opening test at Jerez got off to a slow start, however, as the days progressed so too did Williams.
On the final day, Friday, Massa not only covered 86 laps without issues but he also set the fastest time on the day.
"If you see how we started the first day and the second day, it was not so easy to be sure that we were going to do 86 laps," he said.
"We were able to do more and so many runs I had to stop because of the red flags - things that weren't a problem with the car.
"It's positive that we didn't have any problem to stop the car on the track, any problem that it takes so long to go out again. So that shows evolution."
And the lap times were also worth mentioning.
Massa was quickest on a drying track on the final day while his 1:23.700 from Thursday, the penultimate day of testing, was the second quickest time of the week, 0.424s behind McLaren's Kevin Magnussen.
"I'm happy with the day and I'm happy with the first impression of the team. Definitely [there's] still a lot of work, there's long days in front until the first race.
"It's too early; we cannot forget that it's still testing. And I think this test is maybe even more difficult to explain compared to last year, for example. The rules - nothing changed and now there's a big change, so anything can change in a few days.
"But I'm happy because what I've found inside the team is better than I expected. The team is very good people, very professional people."