Ferrari's Charles Leclerc set the fastest time in practice for the Miami Grand Prix, outpacing Red Bull's Max Verstappen by 0.164 seconds. The session, extended by 30 minutes to allow teams to adapt to recent engine-management rule changes, saw McLaren's Oscar Piastri take third, ahead of Ferrari's Lewis Hamilton.
Mercedes, winners of the first three races this season, encountered difficulties. George Russell, slowed by a turbo issue that was later resolved, finished sixth, 0.790 seconds off the pace. Championship leader Kimi Antonelli could only manage fifth after Mercedes opted not to run him on soft tires while investigating an engine problem.
World champion Lando Norris placed seventh for McLaren, followed by Alpine's Pierre Gasly, Red Bull's Isack Hadjar, and Williams' Carlos Sainz. The session was largely incident-free, though Piastri made slight contact with the wall near the end. Several drivers ran wide braking at the end of the long straights.
Miami hosts a sprint weekend, with qualifying for the shorter sprint race scheduled for 16:30 local time (21:30 BST).