Sebastian Vettel leads the way as the teams break for lunch on the first day of testing at Barcelona, while Lotus takes early bath following chassis problems.

By the time the morning session had ended, the eleven drivers on duty had completed 421 laps, with Marussia's Charles Pic completing the most and Romain Grosjean the least.

The Frenchman will not be running again this afternoon, his team unhappy with the way his car is handling. : "This morning was our first shakedown of our second chassis," said Alan Permane. "Once the car was on track it was soon evident that everything wasn't quite as it should be. As a precaution we are returning the chassis to Enstone for further investigation. Chassis E20-01, which we used in Jerez, is being sent over and we expect to be on track with that chassis tomorrow."

"We completed a few aero runs and then started timed runs," added Grosjean, "but I was very quickly aware that the car wasn't responding as it should. It's not ideal to lose track time, but fortunately we will have the chassis which ran perfectly in Jerez so I should get some good track time tomorrow. It's far better that we have an issue like this now rather than in Melbourne."

A "small issue" was to cost Fernando Alonso track-time also, though the Spaniard managed to complete 37 laps, while Heikki Kovalainen stopped on track around an hour before the lunch break with an unspecified problem.

The new Mercedes, launched before the start of the session, is already looking good, the team clearly benefitting from the day's running at Silverstone at the weekend.

Mid-Session Times - All Times Unofficial