Kimi Raikkonen ended Ferrari’s reign at the top of the timesheets thanks to a C4 tyre run on Wednesday morning in Spain.
The Finn, who left the Scuderia for the rebranded Alfa Romeo team for 2019, posted a 1m17.762 with just over half an hour remaining to finish six-tenths clear of former teammate Sebastian Vettel.
It was still a very good morning for the German four-time Formula 1 champion though as his best was set on the harder, and therefore slower, C3 Pirelli compound.
A number of teams posted their best times of the week so far including Nico Hulkenberg, despite not using DRS on his Renault, in P3 thanks to using the faster C4 rubber.
The two Honda-powered teams, Toro Rosso and Red Bull, would be split by just 0.002s and within the same 1m18.8s bracket as Hulkenberg in fourth and fifth.
Both Daniil Kvyat and Max Verstappen failed to reach 50 laps, however, in the latter’s case, Max completed a number of aero tests in the first two hours as Red Bull understood their RB15.
After making his F1 debut late on Tuesday, development driver Pietro Fittipaldi stayed in the Haas on Wednesday morning and did a very solid job with 48 laps and the sixth best time.
The Brazilian would be responsible for the only red flag of the first four hours, however, as his car came to a halt on the approach to Turn 9 ending his session early.
McLaren has made a good start to testing this year but would be absent for the first two hours of Wednesday as Carlos Sainz only managed 27 laps in the MCL34.
It’s unknown if the British team had any issues or was simply waiting for temperatures to rise in Barcelona.
Sergio Perez was ninth in the Racing Point with Valtteri Bottas bringing up the lap times in the Mercedes, although the Finn would complete the most laps of anyone with 88 to his name.
As for Williams, their car arrived in Spain on Wednesday morning and work has been frantically taking place to get on track after lunch with George Russell set to give the FW42 its long-awaited debut.
Also in the afternoon, Lewis Hamilton and Daniel Ricciardo will return for their respective teams where the focus may well be on race simulations, one of the better barometers of pre-season testing.
A full look at the morning standings in Barcelona can be seen below: