Alfa Romeo’s Zhou Guanyu beat Max Verstappen to lead the second day of 2023 Formula 1 pre-season testing, as Mercedes suffered a mechanical breakdown due to a hydraulic failure.
After taking over from teammate Sergio Pérez for the afternoon session, Verstappen immediately lit up the timetable in his Red Bull RB19 and powered his way to pole position with 1m31.650s on C3 tyres.
The world champion, who also spent the full opening day of a Red Bull test drive on Thursday, was duly ahead in his test program as some competitors didn’t shift their focus to sustained performance until the final hour of the day.
With 30 minutes to go, Zhou, who had completed a full day in an Alfa Romeo C43, strapped on a set of C5 tires and clocked a 1m 31.610s to beat Verstappen by 0.040s.
Mercedes missed the final 90 minutes of on-track action because George Russell suffered a hydraulic failure which left him stuck in fourth gear and triggered the only red flag related to a crash.
Mercedes were left stuck at 98 laps for the day, and Russell added 26 to teammate Lewis Hamilton’s 72 from the morning, as the team investigated the issue and sat at the end of the afternoon session.
Fernando Alonso put his Aston Martin third in overall times with a lap of 1m 32.205sec on C3 tyres, completing the second test day alone with teammate Lance Stroll injured.
F1 rookie Nyck de Vries was another driver to try out softer compounds at the end of the day and went fourth on C4 tires with AlphaTauri.
Nico Hulkenberg moved Haas up to fifth, also helped by a run of C4 compound tyres, to shift Friday morning leader Carlos Sainz into sixth overall for Ferrari.
Logan Sargeant impressed Williams ahead of his rookie season in Formula 1 by scoring 154 laps – the most of any driver on Friday – to finish seventh ahead of Ferrari’s sister Charles Leclerc, who spent the afternoon primarily simulating the race.
Oscar Piastri, McLaren’s new signing, finished ninth despite the team’s MCL60 concerns, with teammate Lando Norris running 16th in the morning session.
Alpine duo Pierre Gasly in 11th and Esteban Ocon 13th split on Haas’ Kevin Magnussen in overall times, ahead of the Mercedes duo who split on Red Bull’s Perez.
The last 15 minutes of both sessions were used for race control procedures, but two late mechanical problems appeared to plague Williams and Alfa Romeo in the afternoon session.
Sargeant jumped the Williams pitlane due to an electrical issue the team was testing, while Cho was retrieved from the pit exit by an Alfa Romeo mechanic after an engine problem.
The 2023 F1 pre-season test in Bahrain wraps up on Saturday.