Valtteri Bottas was fastest for Williams on Sunday in Barcelona as testing wrapped exactly two weeks before the first race in Australia.
Sunday's running was the 12th day of winter testing, and the eighth of the two sessions held in Barcelona. In the morning half, Bottas set the second fastest time seen so far this year at the Spanish GP venue, beaten only by the mark set by Nico Rosberg on Friday. However, while the German used soft tires, Bottas used the supersofts.
"It was a really good day and a great way to finish the test," said Bottas. "One of the main points we have learned is that the FW37 is very reliable. The car we are taking to Melbourne is very competitive and should make for an interesting start to the season."
Sebastian Vettel was second fastest for Ferrari, the former World Champion running supersofts and setting a best time some 0.2s off the best time set by teammate Kimi Raikkonen on Saturday.
"The positive thing is that, once again, we have done a lot of kilometers and gathered useful information," said Vettel. "The fact that our race simulation went more or less as planned is encouraging from a reliability point of view, although this is an aspect where we can still improve. From a performance point of view, it’s clear that Mercedes is still ahead by quite a way, but right behind there is us, Williams and Red Bull, all very close."
Sauber had another solid day as Felipe Nasr logged another 159 laps, and set the third fastest time of the day. Meanwhile, Toro Rosso's Max Verstappen jumped up to fourth spot in the closing stages. Both of the rookies ran the supersofts.
Red Bull had a difficult day with reliability problems keeping Daniel Ricciardo in the garage for much of the time, including some ERS issues, but the Australian did at least get out on soft tires to post the fifth best time of the day.
Sergio Perez had his first outing in the Force India VJM08 after Nico Hulkenberg drove the car for the first two days. The car again proved reliable as Perez logged 130 laps and set the sixth fastest for the day.
After grabbing the headlines on Friday and Saturday, Mercedes played it lowkey, and Nico Rosberg was only seventh fastest with a best time set on mediums, although his lap total of 148 was beaten only by that of Nasr.
It was another frustrating day for McLaren as Jenson Button took over from Kevin Magnussen for the final day, and again hit problems that restricted his running to just 30 laps.
Pastor Maldonado's day ended early when he crashed the Lotus in the afternoon. He finished the session in ninth and last place, having added only 36 laps to the team's winter total.
"It was a shame to end the day early," said Maldonado. "But that was the only issue we’ve had like this during testing so we can look to the positive that we have a lot of information to take the car in the right direction. My braking was compromised coming into Turn 4, meaning I went off the track and hit the barriers.
"I was able to brake and slow, just not as much as the maximum otherwise possible. The car was not too badly damaged and I am fine, but it’s a shame we had this issue as we would have been looking at running the softer tires in the afternoon and putting in some fast laps."
