Lewis Hamilton set the fastest time in FP2 on Thursday at the Bahrain Grand Prix, followed by George Russell as Mercedes laid down a marker on the first day of the season proper.
Max Verstappen was just sixth fastest, behind Fernando Alonso, Oscar Piastri and Carlos Sainz, with questions to be answered on Friday about whether the Red Bull was simply running a higher fuel load or lower engine setting.
Daniel Ricciardo was the fastest driver in the first practice session of the season, beating out the McLarens of Oscar Piastri and Lando Norris.
High winds and low temperatures made the Thursday morning running difficult, but Ricciardo and his VCARB team made the best of the conditions.
Verstappen continued his 2023 form for complaining about his car, telling his garage that 'everything is s***' after setting the fastest lap of the first set of runs, before mithering over the feel of the car on upshifts and downshifts.
The times from the early session aren't expected to be representative of the qualifying order for Friday evening, with different track conditions and teams still looking to key their cars into the circuit - but the second session should be more of a balanced showing.
The only small moment of technical drama came right at the start of the first session, Zhou Guanyu limping into the pits after complaining to his engineers that his brakes 'didn't work', but he quickly got back on track.