Ferrari's Kimi Raikkonen set the fastest time of winter testing so far on his final day in the new SF16-H ahead of the season-opening Australian Grand Prix later this month.
Raikkonen's time of 1:22.765 replaced team-mate Sebastian Vettel's best effort from the first week of testing and set a new benchmark to for the final day of the pre-season on Friday. The time was set on Pirelli's new ultra-soft compound, which reigning champions Mercedes have opted not to use this winter.
Although the ultra-soft time stole the headlines, of more interest was Raikkonen's lap on the yellow-striped soft compound tyre, which beat Nico Rosberg's best effort in the Mercedes using the same compound earlier this week by 0.013s. Testing times on different days rarely offer a fair comparison, but Ferrari's effort sends a message of intent just two weeks remaining before the first race weekend gets underway in Melbourne. Raikkonen went on to complete a race simulation in the afternoon, mimicking Mercedes run plan on the opening days of this week's test.
In terms of outright pace, Felipe Massa was Raikkonen's closest competitor with an impressive 1:23.193 on the soft-compound tyres. The time was within two tenths of the Raikkonen/Rosberg soft tyre target time, suggesting Williams has also made solid progress with its car over the winter.
Nico Hulkenberg set the fourth fastest time using the ultra-soft tyres, but his time of 1:23.251 was over a tenth slower than his best effort on the slower super-soft tyres in the first test. Max Verstappen also made use of the purple ultra-soft tyres to set Toro Rosso's best time of the test with a 1:23.382.
Once again, Mercedes opted to stick to the medium-compound tyres -- the best all-rounders on offer at the test -- and Rosberg used them to set the fifth fastest time with a 1:24.126. He handed over to Hamilton in the afternoon, who managed a best time of 1:26.488, most likely on a heavier fuel load.
Sauber and McLaren focused on mileage and both teams managed well over 100 laps. It was Fernando Alonso's last day behind the wheel of the MP4-31 ahead of the Australian Grand Prix and he set the team's best time of the test with a 1:24.870 on super-soft tyres.
Manor struggled for laps again with just 48 for Pascal Wherlein over the day, while Haas resolved the turbo problem that limited Esteban Gutierrez to one lap on Wednesday. However, the new American team's 78 laps were far from smooth, with Romain Grosjean twice ending up in the gravel either side of the lunch break. The session was brought to an early end when Grosjean was forced to park his car on track 10 minutes before the chequered flag.
Thursday's test day also marked the first public appearance of a new cockpit protection system set to be introduced next year. Raikkonen tested an early development of the Halo device, completing a single lap in the morning with the prototype attached to the SF16-H. Although plans are not yet finalised for 2017, the Halo device is expected to be chosen over a closed canopy, which is also being considered longer term.