SAKHIR, Bahrain - Reigning world champion Max Verstappen sent a signal of intent to his rivals on the final day of preseason testing by setting the fastest lap time of the week by over half a second.
Red Bull brought a significant upgrade package to its RB18 car for the final day of the test on Saturday, and in the evening Verstappen started to explore its potential.
As the sun set over the Bahrain International Circuit, the Dutch driver upped his pace incrementally as he cycled through Pirelli's softest tyre compounds, lowering his lap time to a 1:31.720 on the C5 compound under the floodlights.
Verstappen's best effort was 0.521s faster than any other driver during the test, with Haas driver Mick Schumacher coming closest with a 1:32.241 on the slightly harder C4 compound during an added period of solo testing for the American team at the end of the day. Ferrari's Charles Leclerc was third fastest with a 1:32.415, also on the C4 compound.
Test times are not always an indicator of true performance ahead of a new Formula One season, but at this stage Red Bull and Ferrari are the clear favourites for victory at the opening round in Bahrain next weekend.
"Everyone has more to come," Verstappen said. "Nobody is full beans and qualifying spec at the moment.
"It was just the general progression of the day and just trying a few different tyres. But I think the main focus was also on the tyres we are going to use next week.
"The car was feeling alright and we went through our programme we planned to do and that's always positive I think."
Haas' appearance near the top of the timesheets over the last two days is promising for the team, but it's unlikely it has gone from the back of the grid to the front in the space of a year.
Reigning constructors' champions Mercedes were off the pace of their rivals throughout the test, with Lewis Hamilton and his new teammate George Russell struggling to extract the full performance of the team's latest upgrade.
Russell set the team's fastest lap of the test on Saturday evening, but it was 1.039s off Verstappen using the same tyre compound. It was also slower than Alpine's Fernando Alonso, who set the fourth fastest time, 0.978s off Verstappen, using the C4 compound.
Former Mercedes driver Valtteri Bottas was sixth fastest, but his Alfa Romeo came to a halt at the side of the track shortly after he set a 1:32.285 on the C3 compound tyre. Alfa Romeo had a difficult first test in Spain with numerous reliability issues, but Bottas' time on a relatively hard compound gave some cause for hope at the end of a much more promising second test for the team.
Eighteen of F1's 20 drivers took part in the final day of testing as all but two teams swapped between their drivers during the day. The only drivers to miss out were Alpine's Esteban Ocon, who completed a full day of testing on Friday, and McLaren's Daniel Ricciardo, who tested positive with Covid-19 earlier in the week and is isolating at his hotel until next weekend's race.
Schumacher set his time during an extended two hours of the test for Haas. A delay to the arrival of the team's freight in Bahrain meant it missed Thursday morning's session, so it was agreed among all ten teams that Haas would be granted an extra hour at the end of Friday's running plus one hour ahead of the start of Saturday's test and a further two hours after the chequered flag.
(Tyre compounds in brackets)
1. Verstappen - Red Bull - 1:31.720 (C5) - 53 laps
2. Schumacher - Haas - 1:32.241 (C4) - 85 laps
3. Leclerc - Ferrari - 1:32.415 (C4) - 51 laps
4. Alonso - Alpine - 1:32.698 (C4) - 122 laps
5. Russell - Mercedes - 1:32.759 (C5) - 71 laps
6. Bottas - Alfa Romeo - 1:32.985 (C3) - 68 laps
7. Tsunoda - AlphaTauri - 1:33.002 (C5) - 57 laps
8. Perez - Red Bull - 1:33.105 (C4) - 43 laps
9. Norris - McLaren - 1:33.191 (C3) - 90 laps
10. Vettel - Aston Martin - 1:33.821 (C4) - 81 laps
11. Zhou - Alfa Romeo - 1:33.959 (C4) - 82 laps
12. Gasly - AlphaTauri - 1:34.865 (C4) - 91 laps
13. Sainz - Ferrari - 1:34.905 (C5) - 68 laps
14. Albon - Williams - 1:35.171 (C3) - 18 laps
15. Latifi - Williams - 1:35.634 (C3) - 124 laps
16. Stroll - Aston Martin - 1:36.029 (C3) - 53 laps
17. Hamilton - Mercedes - 1:36.217 (C5) - 78 laps
18. Magnussen - Haas - 1:38.616 (C2) - 38 laps