BARCELONA, Spain (AP) — Mercedes got off to a good start in Formula One's return to Europe, with Valtteri Bottas and Lewis Hamilton setting the pace in practice for the Spanish Grand Prix on Friday.
Bottas led the first session and defending champion Hamilton the second at the Circuit de Barcelona-Catalunya.
Sebastian Vettel, who trails Hamilton by four points in the drivers' standings, kept Ferrari close in the morning session, but Red Bull was the main challenger to Mercedes in the afternoon. Daniel Ricciardo was second and Max Verstappen third.
"We got through all our running and were quite fast compared to previous years," Hamilton said. "It is going to be relatively close between the top three teams but I can't really say who is quickest at the moment."
Bottas was a tenth of a second faster in the morning session than Hamilton's afternoon time at the 4.6-kilometer (2.8-mile) track outside Barcelona.
Most teams brought significant updates to their cars as F1 returned to Europe after races in Australia, Bahrain, China and Azerbaijan. Mercedes and Red Bull appeared to have improved the most, although Ferrari usually shows its best pace in qualifying and in the race.
"Everything we put on the car seems to work and that's important," Vettel said. "We can still work on the car and we should be stronger tomorrow."
Ricciardo, who crashed with Verstappen in Azerbaijan, had a tough start to his weekend in Barcelona by hitting a tire barrier midway through the first session, losing a lot of track time.
"The mistake this morning was a costly one and I missed the final hour of the session because of it," Ricciardo said. "We have found some pace, there is still a bit more to find, but overall a pretty good end to a Friday."
Kimi Raikkonen, in the other Ferrari, was sixth fastest in the afternoon and had to retire late because of an apparent engine problem.
"I was told by the team to stop the car," Raikkonen said." We still don't know what happened, but we'll figure it out."
Crowd-favorite Fernando Alonso was sixth fastest with McLaren in the morning but was 12th in the second session.
Haas and Force India had the best showings of the teams behind the top three of Mercedes, Ferrari and Red Bull.
Robert Kubica, Williams' reserve driver, drove in an official F1 session for the first time since almost losing his right hand in a rally crash in 2011.
The team had to make some modifications to Kubica's car because the Polish driver doesn't have full movement of his right hand.
Kubica finished with the second-to-last time in the first session, in front of teammate Lance Stroll. Sergei Sirotkin was back in the car for the afternoon run.
"In the end it's difficult to say that it was enjoyable because our car balance was very bad and it was very difficult to drive, so it was difficult to enjoy," Kubica said. "But I'm satisfied with the session and with how I reacted to difficult conditions. It sounds strange that you can be happy with P19, but actually I'm happy."
Stroll nearly hit the tire barriers after going off the track with about a half-hour left in the first session.
Many other drivers also struggled to keep their cars on the track, most of the time because of windy conditions.
"You're constantly arriving at each corner and the wind direction is never the same, so we saw lots of drivers going off," Hamilton said. "These conditions make it very difficult to define where the setup needs to go."
Brendon Hartley of Toro Rosso and Romain Grosjean of Haas were among those who went into the gravel in the morning. Bottas and Vettel also spun but were able to continue their runs without significant damage.
Romain Grosjean, who crashed under the safety car in Azerbaijan, was the first to face trouble in the afternoon session, losing control of his Haas and getting stuck on the gravel. Verstappen also went off the track, as did Raikkonen shortly before enduring the mechanical problem.
Sergio Perez had a mechanical issue with Force India and had to retire near the end of the second session.
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