Kimi Raikkonen set the fastest time of pre-season testing so far on the penultimate morning in Barcelona.
The Finn - who completed an installation lap sporting the Halo cockpit protection concept on his Ferrari - set a time of 1:22.765 on the ultrasoft tyre to set a new benchmark for the two tests. Sebastian Vettel had previously held the fastest time - using ultrasofts last week - but Raikkonen beat it by 0.1s.
Raikkonen had already set an eye-catching lap a few minutes earlier when he set the fastest soft tyre lap of the week. With Nico Rosberg having been quickest on softs on Tuesday, Raikkonen went marginally quicker with a little over an hour to go in the morning session.
The top three drivers all set their best times on the ultrasoft tyre, with Nico Hulkenberg second fastest for Force India. Hulkenberg was nearly half a second slower than Raikkonen and ultimately did not beat his best supersoft lap time from the first test.
Max Verstappen was third fastest on the purple-marked tyre, a little over 0.1s shy of Hulkenberg as both drivers tested the softest compound for the first time. Verstappen also had a second run on the tyre in the final 15 minutes before lunch but failed to improve.
Mercedes once again set the standard in terms of mileage with Nico Rosberg racking up 81 laps during the morning session. Rosberg was fourth quickest with Mercedes not planning on running the supersoft or ultrasoft this week. There was also no repeat of the qualifying runs seen on the opening two days, with Rosberg ending up 1.3s off the pace.
A number of teams struggled for mileage somewhat, with Sauber, Renault and Manor all failing to reach 40 laps. While Sauber had also experienced technical issues on Wednesday, Jolyon Palmer will have been left particularly frustrated in the Renault after team-mate Kevin Magnussen completed four consecutive days with over 100 laps. Palmer, however, was hit by reliability issues on the opening two days of the first test and completed just 26 laps this morning to leave him with a total of 105 laps this pre-season so far.
The session ended under a red flag to take the shine off an encouraging morning for Haas. Following just 24 laps over the first two days of the week, Haas enjoyed a productive morning with Romain Grosjean completing 59 laps before he went off at Turn 4 with two minutes remaining. The car came to rest just short of the barrier, with no major damage obvious before it was recovered.
Follow live coverage and timing from pre-season testing here
Keep up to date with all the F1 news via Facebook and Twitter
