Red Bull strength
Sergio Perez continued the strong weekend for Red Bull topping the timesheet ahead of Charles Leclerc's Ferrari and Lando Norris' McLaren.
Not far behind was Pierre Gasly in the Alpha Tauri who was the last to do a fairly competitive run. Esteban Ocon in his Alpine was the first of the runners who did not do a performance run ahead of Haas' Mick Schumacher who outpaced the more positive-looking Mercedes of Valtteri Bottas.
George Russell in the Williams was not too far behind ahead of Kimi Raikkonen in the Alfa Romeo and Lance Stroll in the Aston Martin who only appeared to be working on race runs in the heat of the daylight.
Mercedes conversation continues
In terms of testing, the talk of the day had begun being a day Mercedes need. Yes, Mercedes have not had a great test, but it is a test, you cannot read too much into it until you get to race one, but who does not like a bit of speculation.
The morning session saw all teams not slouching, with Leclerc and Bottas out set times and every other team completing an installation lap within the first 10 minutes of the day.
Leclerc continued the early running so much so that with 25 minutes gone, his Ferrari had knocked off 'MSC' from the top of the timing stand. Despite the reminiscence, Leclerc had put in a 1:30.486 on the C3 tyre, possibly the first representative time of the test and an impressive one at that.
At the end of the first hour, only Gasly had gotten within a second of Leclerc with Perez shortly following again showing the strength of the test that the Honda-powered cars have had.
Run plans proving pivotal
The second hour began as the first played out for most. High fuel runs and long runs left little to no change on the timesheet. Ocon had jumped Perez to add to the list of teams continuing a strong weekend of testing.
Closing toward the half-hour mark of the second hour Perez went for another push on the C2 tyre leaving him 0.441 seconds off the back of Leclerc leaving the top four reinforcing their already established strong tests.
The differences in run plans were ever-present in the first hour and a half with Raikkonen doing longer runs with others that would leave him just inside the 107% if the rule was being applied to this session setting a 1:36.640 with 107% being a 1:36.820.
The second hour was rounded off by a short lul out on track and if anyone did go out on track it was for more long runs in the form of Bottas and Russell.
Then Schumacher came out on the C4 tyre and looked to be heading up the timesheet with two green sectors before understeering in the final corner and losing time leaving him in fifth at the time.
Norris then came round on the C2 tyre to put his McLaren into P2 making what appears to be the midfield ever tighter as there are few teams not putting in strong performances at the time.
Perez starting to stand out
The third hour started with an interesting lap from Perez. On the C3 tyre, Perez did not set personal bests in sectors one and three. In sector two though, he went purple, leaving him half a tenth off of Leclerc.
Gasly was the only other to pick the pace up as times had begun to tumble in the second half of the morning session going purple in the first sector, no personal best in the middle sector, and a personal best in sector three to consolidate the fourth he already had.
Norris was the only one to improve in the next half an hour changing to the C3 tyre. Despite improving, his position had also remained the same leaving him 0.175 seconds behind Leclerc.
Perez followed suit except he did move up a position to the top of the timesheet. An almost coming together with Raikkonen at the last corner to start the lap meant only a personal best first sector as downforce was taken off on this run. Perez then did not set a personal best in the middle sector after being purple previous before setting a purple final sector putting him 0.177 seconds ahead of Leclerc.
The rest of the hour was left for continuous long runs again. Raikkonen still not bettering his 1:36 as he plans to be in the car all day so his quicker laps will come in the afternoon session when the conditions are more like what qualifying what will be in two weeks.
After Perez topped the timesheet earlier, everyone has been out on long runs other than Perez himself and the Williams of Russell who again, like Raikkonen, has the afternoon session ahead of him.
Lap counter rising high
The last hour began as the majority of the third had gone with every car out doing much longer runs on higher fuel. With the limited testing this year it is not believed that many if any teams have run on the full 100kg rather than doing running at around 60kg as an estimate.
The final morning session of testing has also seen a huge reduction in errors and mistakes compared to the first two days. Helped by the wind direction and getting a better understanding of their cars the drivers have got up to speed this year very quickly in canceling out errors.
Perez had continued to slowly build his times up after strapping on a set of C4 tyres and improving his time yet again only by a couple of tenths not quite breaking under the 1:30 barrier.
The second half of the last hour is where we start to get an idea of how each team is playing out. Raikkonen has broken into the 1:35's improving their race run potential with the majority of teams competing over a race run distance.
Mercedes have become more comfortable with their package as Bottas put in the hard work in the morning session whilst the idea of Aston Martin is still unknown. Stroll being the slowest of the 10 drivers in the morning session and even using the relatively unused C1 tyre.
It will be interesting to see if the afternoon session does produce more teams looking at high-performance runs to see if a clear pecking order can be intelligently thought about before testing ends as a whole.