Sebastian Vettel saw Red Bull back to the top of the timesheets on the first day of testing in Barcelona today. Nico Hülkenberg led the way for Force India early on, but it didn't take long for Vettel to jump him, and he never looked back. Many of the teams were putting in long stints, with both Lewis Hamilton and Charles Pic topping the 100 laps mark.

The big news of the day, of course, came from Lotus, who stopped running after just seven laps. They had talked of bringing a spare chassis in, but eventually decided against it. The team won't run for the rest of this test in Barcelona, preferring to make the fixes back in the factory. They are confident they'll be back for the second and final pre-season test next week.

A couple of other teams found they had mechanical troubles as well, with both Caterham, Mercedes and Sauber suffering reliability issues. These weren't quite as severe as the Lotus problem, and the show will go on!

A couple of tweets from the ground:

Another busy and productive day at the track in Barcelona. Nico clocked up 97 laps with a best of 1:23.440, the second fastest of the day.

clubforce

End of the first day of the group test in Barcelona. A good morning with a hydraulic problem then bringing an early end this afternoon...

MercedesAMGF1

Session finished with no lap time improvement. We're still working on data acquisition to understand better the behaviour of the new car.

InsideFerrari