Mercedes had a difficult start to three days of Formula 1 testing in Bahrain.
Lewis Hamilton and team-mate Valtteri Bottas ended the day 10th and 17th fastest and managed the lowest number of laps in the field.
Mercedes had problems with reliability and the handling of the car.
Red Bull’s Max Verstappen was fastest, ahead of McLaren’s Lando Norris, Alpine’s Esteban Ocon, Aston Martin’s Lance Stroll and new Ferrari driver Carlos Sainz.
Conditions were difficult all day, with strong winds and a sandstorm making the track slippery throughout.
The worst period was at the start of the afternoon session, when the track was so dirty that cars were throwing up plumes of sand as they circulated the lap.
But conditions improved later in the day and drivers were able to improve their times.
What went wrong at Mercedes?
World Champions Mercedes’ day started badly when Bottas suffered a gearbox problem after just one lap.
Mercedes decided to change the gearbox and investigate the problem later, but that cost the Finn nearly all his first day’s running and he managed only a further five laps before handing over to Hamilton for the afternoon.
Team principal Toto Wolff said: “It wasn’t a good start because we had a gearbox issue that came out of nowhere that we haven’t yet been able to identify and understand.”
When Hamilton went out at the start of the afternoon session, conditions were at their worst, the Sakhir track enveloped in a sand cloud and conditions on track treacherous, the cars throwing up plumes of sand.
Hamilton found the car’s balance to be poor and returned to the pits for set-up changes.
When he returned to the track, the team concentrated on long runs with high fuel loads and used only the hard ‘C2’ tyres while others explored the faster and grippier C3s and C4s.
Still the car did not look comfortable, though, with Hamilton clearly struggling for grip and having a number of ‘moments’ where he struggled to keep control, ran wide or locked a wheel.
Despite their problems, Mercedes remain strong favourites for the season ahead, having won seven consecutive title doubles since the start of F1’s turbo hybrid engine era in 2014.
Who looked good?
Headline testing times are notoriously misleading as it is impossible to know the specification in which teams are running their cars and fuel loads and engine modes can make significant differences to performance.
Nevertheless, Red Bull’s pre-season got off to a good start as Verstappen displayed strong pace on both the C2 and C3 tyres, well clear of the rest of the field on both compounds.
The Dutchman, who had a spin at Turn Two early in the day, set his fastest time on the C3 tyre and ended the day 0.4secs clear of any other driver, and more than a second quicker than the second fastest driver on the medium tyre.
McLaren also had a strong day as Lando Norris and new signing Daniel Ricciardo had their first real experience of the Mercedes engine to which the team have switched this season.
Ricciardo was fastest of all in the morning session, while Norris was second fastest in the later running, just over 0.2secs slower than Verstappen.
Team principal Andreas Seidl said: “It worked out fine.
“From the Mercedes side, there was no issue. It was also very important that Daniel got his first taste of McLaren in full anger. He has invested a lot of energy to ensure he was ready.
“So far so good. We still have a lot of work to do but I am confident we will be ready for the first race.”
Esteban Ocon’s Alpine was third fastest, using the softer C4 tyre for his best lap for what was formerly the Renault team.
And Lance Stroll went fourth quickest late in the day for Aston Martin, formerly known as Racing Point. His new team-mate Sebastian Vettel ran in the hotter conditions of the morning session and ended the day 13th fastest.
Mick Schumacher was another to suffer with reliability problems, a hydraulic issue in the morning restricting the son of seven-time champion Michael to just 15 laps.
FASTEST TIMES, 2021 PRE-SEASON TESTING, DAY ONE, SAKHIR, BAHRAIN
1 Max Verstappen (Ned) Red Bull 1:30.674 ***
2 Lando Norris (GB) McLaren 1:30.889 ***
3 Esteban Ocon (Fra) Alpine 1:31.146 ****
4 Lance Stroll (Can) Aston Martin 1:31.782 +
5 Carlos Sainz (Spa) Ferrari 1:32.869 ***
6 Antonio Giovinazzi (Ita) Alfa Romeo 1:31.945 ***
7 Daniel Ricciardo (Aus) McLaren 1:32.203 ***
8 Pierre Gasly (Fra) Alpha Tauri 1:32.231 ***
9 Yuki Tsunoda (Jpn) Alpha Tauri 1:32.727 **
10 Lewis Hamilton (GB) Mercedes 1:32.912 **
11 Charles Leclerc (Mon) Ferrari 1:33.242 ***
12 Kimi Raikkonen (Fin) Alfa Romeo 1:33.320 **
13 Sebastian Vettel (Ger) Aston Martin 1:33.742 ***
14 Roy Nissany (Isr) Williams 1:34.789 ***
15 Nikita Mazepin (Rus) Haas 1:34.798 ***
16 Mick Schumacher (Ger) Haas 1:36.127 **
17 Valtteri Bottas (Fin) Mercedes 1:36.850 **
Key: ** = C2 (hard) tyre; *** = C3 (medium) tyre; + = C3 development tyre