Follow live coverage of the final day of the first pre-season test from Circuit de Barcelona-Catalunya with F1i.
After three days of testing so far, Mercedes remains in ominous form as it continues to complete impressive mileage. Such has been the reliability of the new W07, the team is going to split the driving between both Lewis Hamilton and Nico Rosberg for the remainder of pre-season, with both driving for half a day each again on day four.
Mercedes is also set to have a new nose on the car on Thursday, which was ready to go on day three. The team opted not to use the upgrade during yesterday's running as it was still evaluating other new parts - including its innovative floor - and wanted to maintain a stable baseline.
Another team looking to improve on disrupted running will be McLaren, with Jenson Button's third day schedule being curtailed early due to a hydraulic leak. Fernando Alonso returns to the car for the final day of the first test having completed more than 100 laps already on Tuesday.
You can follow live coverage of both pre-season tests - including live timing - on F1i's live page here, while there are also galleries of all of the new cars.
Running will take place from 0900-1300 and 1400-1800 every day throughout the two tests, with the first taking place from February 22-25 and the second being held from March 1-4.