AlphaTauri's Pierre Gasly was the quickest man on track during the opening day of testing in Bahrain, with the French driver clocking a 1:33.902 on the Soft C5 compound.
But it was Red Bull which logged the most miles during the day, despite Sergio Perez spinning off in the final minutes.
With sheer lap count being a primary goal of pre-season testing as teams strive for mileage to better understand their new cars, Mercedes also featured towards the top of the mileage charts.
Interestingly, Alfa Romeo started the Bahrain test strongly after struggling for reliability during the opening three days in Barcelona.
Haas, which missed the morning session as a logistics issue meant they didn't arrive at the Sakhir circuit on time, were, unsurprisingly, at the bottom of the pile as they logged just 47 laps with Pietro Fittipaldi during the afternoon.
McLaren also struggled to get the laps in after being one of the top performers in Barcelona. After spending large chunks of the day in the garage, Lando Norris could only put in 50 laps.
Bahrain F1 testing lap count by team (Day 1 - Thursday)
Perez the most productive driver
In terms of the individual lap charts, Perez led the way as he put in almost two full Grand Prix distances of the circuit.
Alex Albon also racked up the miles as he logged 104 laps for Williams, while pace-setter Gasly was up next with 103 laps in total. Most other teams split their running between their two drivers.
At the bottom of the table, Fernando Alonso did the least amount of mileage as he recorded just 24 laps during the afternoon after taking over from Alpine teammate Esteban Ocon in the morning.
Bahrain F1 testing lap count by driver (Day 1 - Thursday)