Testing Day 1: Verstappen tops the timesheet, Mercedes struggle

The Dutchman completed both the morning and afternoon session. His fastest lap of the day was recorded on the medium tyre. The hard tyre was the most popular choice of compound around the Bahrain International Circuit during Day 1. Only briefly did we see the C4 soft tyre on Ocon's car. 

Alpine driver Esteban Ocon also completed the full eight hours of running. He rivalled Verstappen on the lap counter and stopwatch. Lando Norris and Ocon rounded out the top three. 

Mercedes struggled with a transmission issue during the first part of the day. Bottas completed just six laps and Hamilton was forced to sit inside the garage during the first hour of his allotted time. 

A sandstorm hit the circuit when running resumed after the lunch break, but it didn't cause any red flags. The only red flag was caused by Charles Leclerc who stopped out on the track at turn four just prior to the mid-session interval. 

Winners

Without a doubt, the McLaren team are the big winners of day one. The Woking-based team perhaps had more work than anyone over the winter because they changed engine supplier. The Mercedes engine certainly hasn't caused any harm with both Lando Norris and Daniel Ricciardo sitting in the top ten.

The Red Bull car looked a bit twitchy in the opening laps. Verstappen spun a couple of times on the track but the windy conditions more than likely caused this. Any of those issues seemed to be fine-tuned over the lunch break and the RB16B looked sharp under the floodlights. 

AlphaTauri will also be sitting comfortable overnight. A lot of running for both Pierre Gasly and Yuki Tsunoda. And Carlos Sainz toppled his teammate Charles Leclerc on day one. Of course, fuel levels and run types are unknown but the Spaniard can be pleased with his first full day in the Ferrari cockpit. 

And Williams will be pleased with their running during the first eight hours of testing. Roy Nissany sat in the cockpit for the duration of the day and completed over 76 laps. He might have finished in P14, but the team look to be faster than Haas. 

Losers 

Mercedes. Towards the end of the day, Hamilton managed to stack up the mileage but the missed running in the morning is time they won't get back. And even during Hamilton's afternoon runs, the car didn't look as comfortable as a normal Mercedes does. Toto Wolff and co won't be worrying yet, however. 

Even though Lance Stroll was late out of the garage in the second half of the day, Aston Martin recorded plenty of data. A messy day, but the team worked hard on performance runs. In the final 30 minutes, Stroll produced a 1:31.782 which was enough to take him into the top four.